what is oil type sorento use ?
Is it safe to use synthetic on new sorento ?
Is it safe to use synthetic on new sorento ?
what is oil type sorento use ?
picard12
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Now I don't want to "derail" this thread any further by pursuing this back-and-forth conversation about this guy's "blog" so I'll just make this one final comment about it.
I have known about RAT's (Rick Jackson) Blog for some time. His "540 RAT" handle comes from his "540 Big Block Chevy 'Rat' Street Hot Rod Engine".
As I said above, I don't deny that it does contain some good "general" info about motor oil. What I do question however, is the validity of his "results" and how he actually arrived at those results (equipment and testing procedures used) as well as the actual real-world applicability and relevance of the tests performed.
He doesn't perform any of his tests in an actual car engine, he doesn't tell us anything about his testing equipment (it's proprietary), he doesn't reveal his testing methodology (it's a secret), there is no error analysis done, he doesn't tell us how many trials he conducted, etc... he just expects us to accept his "numbers" simply out of 'blind faith'. "Trust me, I'm an Engineer!"
Additionally, his "proprietary test" is NOT an industry accepted test and has NOT been peer reviewed or validated by any certification body (i.e. ASTM, API, ACC) - not to mention that "bench tests" are not the most reliable indicators of actual field performance. But that doesn't stop him from making this claim regarding his covert test: "There is no additional value to performing more comprehensive oil testing related to wear prevention..."
Here are a few comments from "industry experts" about RAT's "test":
I suggest you read these two recent articles on "xtremerevolution.net":
Exposting The Flaws In 540 RAT's Engineering Test Data Blog
...and his follow-up article:
Exposing The Flaws In 540 RAT's Rebuttal
Here is a link to a post about his original test on Mar 19, 2012:
TheSamba.com forum, second post on the page by "Quokka42"
Here are two more threads from 2012/13 (both started by 540 RAT):
Lars and 540 RAT’s Oil Testing (speedtalk.com)
Motor Oil "Wear Test" and "Lab Test" Data (corvetteforum.com)
For further discussion and information, I suggest you check-out these threads on the "BITOG Forums":
From Sep 2015: 540 Rat oil tests
From Feb 2017: 540 Rat Blog - QSUD better than Mobil 1
From Dec 2017: 540RAT Blog
'nuff said!
![Image]()
I have known about RAT's (Rick Jackson) Blog for some time. His "540 RAT" handle comes from his "540 Big Block Chevy 'Rat' Street Hot Rod Engine".
As I said above, I don't deny that it does contain some good "general" info about motor oil. What I do question however, is the validity of his "results" and how he actually arrived at those results (equipment and testing procedures used) as well as the actual real-world applicability and relevance of the tests performed.
He doesn't perform any of his tests in an actual car engine, he doesn't tell us anything about his testing equipment (it's proprietary), he doesn't reveal his testing methodology (it's a secret), there is no error analysis done, he doesn't tell us how many trials he conducted, etc... he just expects us to accept his "numbers" simply out of 'blind faith'. "Trust me, I'm an Engineer!"
Additionally, his "proprietary test" is NOT an industry accepted test and has NOT been peer reviewed or validated by any certification body (i.e. ASTM, API, ACC) - not to mention that "bench tests" are not the most reliable indicators of actual field performance. But that doesn't stop him from making this claim regarding his covert test: "There is no additional value to performing more comprehensive oil testing related to wear prevention..."
Here are a few comments from "industry experts" about RAT's "test":
And here's another one:
And here's one from a Certified Lubrication Specialist:
And here's another one:
I suggest you read these two recent articles on "xtremerevolution.net":
Exposting The Flaws In 540 RAT's Engineering Test Data Blog
...and his follow-up article:
Exposing The Flaws In 540 RAT's Rebuttal
Here is a link to a post about his original test on Mar 19, 2012:
TheSamba.com forum, second post on the page by "Quokka42"
Here are two more threads from 2012/13 (both started by 540 RAT):
Lars and 540 RAT’s Oil Testing (speedtalk.com)
Motor Oil "Wear Test" and "Lab Test" Data (corvetteforum.com)
For further discussion and information, I suggest you check-out these threads on the "BITOG Forums":
From Sep 2015: 540 Rat oil tests
From Feb 2017: 540 Rat Blog - QSUD better than Mobil 1
From Dec 2017: 540RAT Blog
'nuff said!
You can rest assure that using synthetic oil is the best thing you can use on your vehicle. I've been using synthetic oil before it was available to the public and since then I have never used anything else. Back in 1991, I bought a brand new 1992 Ford F 150 and I put 485,000 miles on it when I sold it. I never had to do any interior work on the engine. Used to change the oil once a year, that was it. Used to be my daily driver and used to put 120 miles a day, to go back and forth from work.
Now that I have my new Sorrento, after my free oil change that I am going to get from the dealer for the nest three years, I will definitely will go to synthetic.
485,000 miles !!!!
That's like over 780,530 KM
I guess you have my measly 400,000 KM beat.
Pretender, I usually put a lot of miles on my vehicles.
The American Automobile Association (AAA) is one of the most recent company to promote the benefits of using synthetics. The popular club recently conducted in-depth testing to determine if it’s worth paying more for synthetic oil over conventional oil.
"Oil protects critical engine components from damage and AAA found that synthetic engine oils performed an average of 47 percent better than conventional oils in a variety of industry-standard tests," said John Nielsen, AAA’s managing director of Automotive Engineering and Repair.
"With its superior resistance to deterioration, AAA’s findings indicate that synthetic oil is particularly beneficial to newer vehicles with turbo-charged engines and for vehicles that frequently drive in stop-and-go traffic, tow heavy loads or operate in extreme hot or cold conditions."
AAA’s research included eight industry-standard ASTM tests focusing on 'shear stability', 'deposit formation', 'volatility', 'cold-temperature pumpability', 'oxidation resistance' and 'oxidation-induced rheological changes'. Each test was performed on five synthetic and five conventional oils.
The results were published in May 2017:
AAA Engine Oil ResearchReport (PDF)
Pretender
"Oil protects critical engine components from damage and AAA found that synthetic engine oils performed an average of 47 percent better than conventional oils in a variety of industry-standard tests," said John Nielsen, AAA’s managing director of Automotive Engineering and Repair.
"With its superior resistance to deterioration, AAA’s findings indicate that synthetic oil is particularly beneficial to newer vehicles with turbo-charged engines and for vehicles that frequently drive in stop-and-go traffic, tow heavy loads or operate in extreme hot or cold conditions."
AAA’s research included eight industry-standard ASTM tests focusing on 'shear stability', 'deposit formation', 'volatility', 'cold-temperature pumpability', 'oxidation resistance' and 'oxidation-induced rheological changes'. Each test was performed on five synthetic and five conventional oils.
The results were published in May 2017:
AAA Engine Oil ResearchReport (PDF)
Pretender
KIA recommends Synthetic Motor Oil
The reasons I strongly recommend using Synthetic Oil in KIA vehicles (especially GDI and GDI-Turbo models) are:
1- KIA themselves (corporate) recommends synthetic oil - the Owner’s Manual mentions Total Quartz and KIA specifies QUARTZ 9000 ENERGY HKS G-310 which is a Full Synthetic motor oil (API SM - ACEA A5) [About API & ACEA]. Additionally, "kiatechinfo.com" also recommends other synthetic oil brands.
However, I should probably point out that this oil does NOT meet the latest North-American API SN standard (it is only API SM certified).
Note: The reason that KIA MOTORS recommends TOTAL oils is because they have a partnership/contract with them (since 2011) - it's NOT because TOTAL oil is necessarily the best oil for KIA engines (or the only oil that can/should be used in them). Car manufacturers form partnerships with different oil companies all the time; this is a common practice.
KIA MOTORS CORPORATION recommends TOTAL
2- It also appears that KIA vehicles leaves the factory with synthetic oil as the initial fill (at least in "participating" countries) "This lubricant is used by Hyundai- Kia Motors Corporation for First Fill." [view PDF].
3- GDI (Gasoline Direct Injection) engines are much harder on oil than regular fuel injection engines. And if you have the Turbo model (T-GDI), then it's even more critical to use a high quality synthetic motor oil.
4- Full Synthetic oil is superior to Conventional oil. It delivers superior protection and performance in temperature extremes (hot or cold); keeps your engine cleaner by significantly reducing the formation of sludge and varnish; resists oxidation and acid formation; and provides unsurpassed friction reduction and wear protection for extended drain intervals. [See: Why Synthetics?]
This is a proven FACT that has been demonstrated by countless independent "unbiased" tests over the years. Many of those tests involved actual car engines in real-world testing over countless miles in various conditions.
For instance, check the two field studies below:
Las Vegas Taxi Cab Field Study
Diesel Fleet Fuel Economy Study
Richard
The reasons I strongly recommend using Synthetic Oil in KIA vehicles (especially GDI and GDI-Turbo models) are:
1- KIA themselves (corporate) recommends synthetic oil - the Owner’s Manual mentions Total Quartz and KIA specifies QUARTZ 9000 ENERGY HKS G-310 which is a Full Synthetic motor oil (API SM - ACEA A5) [About API & ACEA]. Additionally, "kiatechinfo.com" also recommends other synthetic oil brands.
However, I should probably point out that this oil does NOT meet the latest North-American API SN standard (it is only API SM certified).
Note: The reason that KIA MOTORS recommends TOTAL oils is because they have a partnership/contract with them (since 2011) - it's NOT because TOTAL oil is necessarily the best oil for KIA engines (or the only oil that can/should be used in them). Car manufacturers form partnerships with different oil companies all the time; this is a common practice.
KIA MOTORS CORPORATION recommends TOTAL
2- It also appears that KIA vehicles leaves the factory with synthetic oil as the initial fill (at least in "participating" countries) "This lubricant is used by Hyundai- Kia Motors Corporation for First Fill." [view PDF].
3- GDI (Gasoline Direct Injection) engines are much harder on oil than regular fuel injection engines. And if you have the Turbo model (T-GDI), then it's even more critical to use a high quality synthetic motor oil.
4- Full Synthetic oil is superior to Conventional oil. It delivers superior protection and performance in temperature extremes (hot or cold); keeps your engine cleaner by significantly reducing the formation of sludge and varnish; resists oxidation and acid formation; and provides unsurpassed friction reduction and wear protection for extended drain intervals. [See: Why Synthetics?]
This is a proven FACT that has been demonstrated by countless independent "unbiased" tests over the years. Many of those tests involved actual car engines in real-world testing over countless miles in various conditions.
For instance, check the two field studies below:
Las Vegas Taxi Cab Field Study
Diesel Fleet Fuel Economy Study
Richard
That AAA PDF is very detailed and telling. I am going to officially base-line my car just in case the dealership didn't use synthtic when they changed it last...they have a sticker on the window but it only says 5W-30 and nothing about oil type. Thanks for all of this great information!
Well that's just crazy. If she didn't read the dipstick how does she know it needs that much oil?
Conventional vs. Synthetic vs. Synthetic Blend
Engine Lubricants create a lubricating film between surfaces of adjacent moving parts minimizing direct contact between them, decreasing heat caused by friction and reducing wear, thus protecting the engine. Coating metal surfaces with oil also keeps them from being exposed to oxygen, inhibiting oxidation at elevated operating temperatures and preventing rust or corrosion.
Motor oil also serves as a cooling agent. In some engines oil is sprayed through a nozzle inside the crankcase onto the piston to provide cooling of specific parts that undergo high temperature strain. In use, the oil transfers heat through convection as it flows through the engine, by means of air flow over the surface of the oil pan, an oil cooler, and through the buildup of oil gases evacuated by the Positive Crankcase Ventilation (PCV) system.
It is generally accepted that synthetics outperform conventional oils, but many people don’t understand why. The differences begin at a molecular level.
Motor oil is made up of two basic components: Base stock and Additives.
A Base Stock can be either a mineral (petroleum-based) hydrocarbon or a synthesized (engineered) chemical compound. The base stock comprises the bulk of the oil’s volume (70 to 80 percent). The base stock lubricates internal moving parts, removes heat and seals piston rings.
Motor oil base stocks can be made from either:
A. Petroleum/Crude Oil (Conventional Lubricants)
B. Chemically Synthesized Materials (Synthetic Lubricants) or
C. A Combination of Both (Synthetic Blends)
A. Conventional Lubricants
Conventional lubricants – the oils most people are familiar with – are refined from crude oil that has been pumped from the ground.
The problem with crude oil is that it contains hundreds of different types of hydrocarbon molecules all mixed together. You have to separate the different types of hydrocarbons to have anything useful.
The oil refining process separates the various types of molecules in the oil by weight, leaving molecules similar in weight but dissimilar in structure. Since the refining process cannot distinguish such molecules, the result is a lubricant with a wide assortment of molecules of different shapes and sizes.
Because the assorted molecules of refined lubricants are of different shapes and sizes, the lubricant surfaces are irregular at the molecular level. As lubricant layers flow across one another during the lubrication process, these irregularities create friction within the fluid itself, which consumes power, reduces efficiency and increases heat and wear.
Some of the substances in crude oil are detrimental to lubrication. Paraffin (wax), for example, is a common conventional oil contaminant that causes motor oil to thicken in cold temperatures. Sulfur is a naturally occurring inorganic element that readily reacts with oxygen molecules and is detrimental to oil performance.
Contaminating elements are inherent to crude oil and cannot be completely removed through the refining process and invite the formation of sludge and other products of lubricant breakdown.
B. Synthetic Lubricants
Synthetic Lubricants, on the other hand, are chemically engineered (synthesized) from pure chemicals rather than refined from crude oil.
Synthetic lubricants contain no contaminants or molecules that don't serve a designed purpose. Their components are chemically reacted to produce finished products with pre-designed performance characteristics. That gives them significant advantages over refined oils.
Feed-stocks from which synthetic lubricants are made do not contain sulfur, paraffin, nitrogen or other elements that invite the formation of sludge and other products of lubricant breakdown. Synthetic lubricants can be used in higher temperatures than refined lubricants without breaking down. Their resistance to breakdown also allows them to be used for longer periods than refined lubricants. Lubricated systems stay cleaner and last longer.
Synthetic Oil is chemically engineered for a certain molecular composition with a tailored and uniform structure. Their smooth, uniform lubricating molecules slip easily across one another, and because of their molecular uniformity, they excel in reducing friction, which improves fuel efficiency and economy, controls heat, and reduces wear. This molecular uniformity also helps synthetics resist thinning in hot temperatures and thickening in cold.
In short, synthetics' versatility and pure, uniform molecular structure impart properties that provide better friction-reduction and wear protection, optimum fuel efficiency and superior film strength, a greater ability to resist shearing forces and viscosity breakdown, and extreme-temperature performance conventional lubricants just can't touch.
C. Synthetic Blends
A lower cost alternative to Full Synthetic motor oil is a Synthetic Blend / Semi-Synthetic motor oil.
A Synthetic Blend typically mixes anywhere from 60 to 80 percent conventional oil with 20 to 40 percent synthetic oil. Since there are no regulatory controls on what actual percentage mix constitutes a synthetic blend, the percentage of synthetic oil content can be even lower than 20 percent; therefore price and performance variation between various brands will occur.
You can also create your own "blend" by simply substituting a quart or two of full synthetic oil for conventional oil when you change your oil; most synthetic oils are totally compatible with conventional oils. The implication is superior performance at a lower cost. However, even if the base oils are compatible, there is the prospect that the additives used to create necessary performance properties could conflict, producing a lost in lubricant effectiveness.
Although a blended product offers some of the advantages of a full synthetic for less cost, it cannot match or compete with the performance level of full synthetic oil due to the refined oil content and generally does not support extended oil drain intervals.
Many of today's multi-grade "Full Synthetic" oils are actually in fact "Synthetic Blends" [See the next post below for more on this].
Motor Oil Additives
When Motor Oil is blended, many chemicals (additives) are added to the oil.
Additives impart new characteristics to the oil, or improve existing characteristics, enabling it to function in a desired manner when used to lubricate an engine. Additives improve the overall performance of the fluid.
Additives are used to enhance the beneficial properties of the base oil, helping it stand up to extreme operating environments, and make up for its deficiencies. Even the best base oil would not be able to protect as well against the effects of heat, shearing forces, chemical and water dilution, corrosion and wear particles. In short, additives make good base oils even better.
The various chemicals that comprise the additive system help modern Lubricants meet the increasing demands of today's high-tech engines. For passenger car motor oils, the base stock makes up 70 to 80 percent of the final product; the other 20 to 30 percent is comprised of additive chemistry.
It’s important to note that most additives are also sacrificial. Once they are gone, they’re gone. A proper oil analysis report can determine the health of the additives remaining in the lubricant.
For more, see:
What Is Motor Oil? Part 1: Petroleum & Hydrocarbons
What Is Motor Oil? Part 2: Motor Oil Base Stock
What Is Motor Oil? Part 3: Motor Oil Additives
Engine Lubricants create a lubricating film between surfaces of adjacent moving parts minimizing direct contact between them, decreasing heat caused by friction and reducing wear, thus protecting the engine. Coating metal surfaces with oil also keeps them from being exposed to oxygen, inhibiting oxidation at elevated operating temperatures and preventing rust or corrosion.
Motor oil also serves as a cooling agent. In some engines oil is sprayed through a nozzle inside the crankcase onto the piston to provide cooling of specific parts that undergo high temperature strain. In use, the oil transfers heat through convection as it flows through the engine, by means of air flow over the surface of the oil pan, an oil cooler, and through the buildup of oil gases evacuated by the Positive Crankcase Ventilation (PCV) system.
It is generally accepted that synthetics outperform conventional oils, but many people don’t understand why. The differences begin at a molecular level.
Motor oil is made up of two basic components: Base stock and Additives.
A Base Stock can be either a mineral (petroleum-based) hydrocarbon or a synthesized (engineered) chemical compound. The base stock comprises the bulk of the oil’s volume (70 to 80 percent). The base stock lubricates internal moving parts, removes heat and seals piston rings.
Motor oil base stocks can be made from either:
A. Petroleum/Crude Oil (Conventional Lubricants)
B. Chemically Synthesized Materials (Synthetic Lubricants) or
C. A Combination of Both (Synthetic Blends)
A. Conventional Lubricants
Conventional lubricants – the oils most people are familiar with – are refined from crude oil that has been pumped from the ground.
The problem with crude oil is that it contains hundreds of different types of hydrocarbon molecules all mixed together. You have to separate the different types of hydrocarbons to have anything useful.
The oil refining process separates the various types of molecules in the oil by weight, leaving molecules similar in weight but dissimilar in structure. Since the refining process cannot distinguish such molecules, the result is a lubricant with a wide assortment of molecules of different shapes and sizes.
Because the assorted molecules of refined lubricants are of different shapes and sizes, the lubricant surfaces are irregular at the molecular level. As lubricant layers flow across one another during the lubrication process, these irregularities create friction within the fluid itself, which consumes power, reduces efficiency and increases heat and wear.
Some of the substances in crude oil are detrimental to lubrication. Paraffin (wax), for example, is a common conventional oil contaminant that causes motor oil to thicken in cold temperatures. Sulfur is a naturally occurring inorganic element that readily reacts with oxygen molecules and is detrimental to oil performance.
Contaminating elements are inherent to crude oil and cannot be completely removed through the refining process and invite the formation of sludge and other products of lubricant breakdown.
B. Synthetic Lubricants
Synthetic Lubricants, on the other hand, are chemically engineered (synthesized) from pure chemicals rather than refined from crude oil.
Synthetic lubricants contain no contaminants or molecules that don't serve a designed purpose. Their components are chemically reacted to produce finished products with pre-designed performance characteristics. That gives them significant advantages over refined oils.
Feed-stocks from which synthetic lubricants are made do not contain sulfur, paraffin, nitrogen or other elements that invite the formation of sludge and other products of lubricant breakdown. Synthetic lubricants can be used in higher temperatures than refined lubricants without breaking down. Their resistance to breakdown also allows them to be used for longer periods than refined lubricants. Lubricated systems stay cleaner and last longer.
Synthetic Oil is chemically engineered for a certain molecular composition with a tailored and uniform structure. Their smooth, uniform lubricating molecules slip easily across one another, and because of their molecular uniformity, they excel in reducing friction, which improves fuel efficiency and economy, controls heat, and reduces wear. This molecular uniformity also helps synthetics resist thinning in hot temperatures and thickening in cold.
In short, synthetics' versatility and pure, uniform molecular structure impart properties that provide better friction-reduction and wear protection, optimum fuel efficiency and superior film strength, a greater ability to resist shearing forces and viscosity breakdown, and extreme-temperature performance conventional lubricants just can't touch.
C. Synthetic Blends
A lower cost alternative to Full Synthetic motor oil is a Synthetic Blend / Semi-Synthetic motor oil.
A Synthetic Blend typically mixes anywhere from 60 to 80 percent conventional oil with 20 to 40 percent synthetic oil. Since there are no regulatory controls on what actual percentage mix constitutes a synthetic blend, the percentage of synthetic oil content can be even lower than 20 percent; therefore price and performance variation between various brands will occur.
You can also create your own "blend" by simply substituting a quart or two of full synthetic oil for conventional oil when you change your oil; most synthetic oils are totally compatible with conventional oils. The implication is superior performance at a lower cost. However, even if the base oils are compatible, there is the prospect that the additives used to create necessary performance properties could conflict, producing a lost in lubricant effectiveness.
Although a blended product offers some of the advantages of a full synthetic for less cost, it cannot match or compete with the performance level of full synthetic oil due to the refined oil content and generally does not support extended oil drain intervals.
Many of today's multi-grade "Full Synthetic" oils are actually in fact "Synthetic Blends" [See the next post below for more on this].
Motor Oil Additives
When Motor Oil is blended, many chemicals (additives) are added to the oil.
Additives impart new characteristics to the oil, or improve existing characteristics, enabling it to function in a desired manner when used to lubricate an engine. Additives improve the overall performance of the fluid.
Additives are used to enhance the beneficial properties of the base oil, helping it stand up to extreme operating environments, and make up for its deficiencies. Even the best base oil would not be able to protect as well against the effects of heat, shearing forces, chemical and water dilution, corrosion and wear particles. In short, additives make good base oils even better.
The various chemicals that comprise the additive system help modern Lubricants meet the increasing demands of today's high-tech engines. For passenger car motor oils, the base stock makes up 70 to 80 percent of the final product; the other 20 to 30 percent is comprised of additive chemistry.
It’s important to note that most additives are also sacrificial. Once they are gone, they’re gone. A proper oil analysis report can determine the health of the additives remaining in the lubricant.
For more, see:
What Is Motor Oil? Part 1: Petroleum & Hydrocarbons
What Is Motor Oil? Part 2: Motor Oil Base Stock
What Is Motor Oil? Part 3: Motor Oil Additives
Base Oil Groups
Base Oil Classification System
The American Petroleum Institute’s (API) "Base Oil Classification System" classifies base oils into five major Groups based on the level of Saturates, Sulfur and Viscosity Index. Before all the additives are added to the mixture, lubricating oils begin as one or more of these five API groups.
The first three Groups are refined from petroleum crude oil. Group IV base oils are fully synthesized poly-alpha-olefin (PAO) oils. Group V is for all other base oils not included in Groups I through IV.
In general, the chemical composition and performance properties of the base oil categories improve with advancing group number. For instance, Group I base oils have a lower concentration of saturates (saturated molecules) than Group II base oils, while Group II base oils have a lower concentration of saturates than Group III base oils, and so on.
The higher the number of Saturates, the higher the molecular bond strength of the oil and therefore the better the resistance to breakdown or loss of viscosity; the lower the Sulphur content, the better the purity and thus the lower the corrosive and oxidation potential; the higher the Viscosity Index, the less the base oil’s viscosity will change with changes in temperature and therefore less Viscosity Index Improver (VII) additives will be required, the more shear stable it will be, and the longer it will last.
Today, base oils from Groups III, IV and V are considered “synthetic”. However, only base oils from Groups IV and V are truly 100% synthetic (as per the original definition of a full synthetic motor oil).*
Group IV Polyalphaolefins (PAOs), which are made from very small uniform molecules, are chemically engineered through a process called synthesizing and therefore are considered true 100% synthetic base oils. Polyalphaolefins provide excellent performance characteristics and have few negative attributes.
PAO base oils are actually similar to mineral oils. The advantage comes from the fact that they are built, rather than extracted and modified, making them more pure. Since they are "man-made", they are tailored to have a controlled molecular structure with predictable properties.
* In 1999 the National Advertising Division (NAD) of the Better Business Bureau, in response to a complaint from ExxonMobil, ruled that Castrol Syntec, which was based on a Group III+ base oil, could be considered "synthetic" because modern oils made using Severe Hydrocracking and Hydro-isomerization technology have most of the same performance features of a "true" Synthetic.
In light of this 'non-binding' ruling, the rest of the major oil manufacturers and blenders decided it was safe to expand that interpretation to cover all Group III base oils and proceeded to do so. It was a low risk marketing decision betting that no one would challenge the move after the NAD ruling, and they were right, no one did.
As a result, the synthetic line was drawn by the oil marketers between Group II+ and Group III base oils. This took pretty much all of the meaning out of the term "synthetic".
However, only Groups IV & V base oils are truly 100% Synthetic.
Note: In some European countries (e.g. Germany), unlike in North America, only Groups IV and V based motor oils can be labelled "Synthetic".
Now that said, what truly matters in the end however, is the quality and performance of the finished blended product. The point is, a motor oil can’t be judged solely by its base oils – you need to take the entire formulation into account (base stock plus additives).
LINK: Base Oil Classification System
Richard
Base Oil Classification System
The American Petroleum Institute’s (API) "Base Oil Classification System" classifies base oils into five major Groups based on the level of Saturates, Sulfur and Viscosity Index. Before all the additives are added to the mixture, lubricating oils begin as one or more of these five API groups.
The first three Groups are refined from petroleum crude oil. Group IV base oils are fully synthesized poly-alpha-olefin (PAO) oils. Group V is for all other base oils not included in Groups I through IV.
In general, the chemical composition and performance properties of the base oil categories improve with advancing group number. For instance, Group I base oils have a lower concentration of saturates (saturated molecules) than Group II base oils, while Group II base oils have a lower concentration of saturates than Group III base oils, and so on.
The higher the number of Saturates, the higher the molecular bond strength of the oil and therefore the better the resistance to breakdown or loss of viscosity; the lower the Sulphur content, the better the purity and thus the lower the corrosive and oxidation potential; the higher the Viscosity Index, the less the base oil’s viscosity will change with changes in temperature and therefore less Viscosity Index Improver (VII) additives will be required, the more shear stable it will be, and the longer it will last.
Today, base oils from Groups III, IV and V are considered “synthetic”. However, only base oils from Groups IV and V are truly 100% synthetic (as per the original definition of a full synthetic motor oil).*
Group IV Polyalphaolefins (PAOs), which are made from very small uniform molecules, are chemically engineered through a process called synthesizing and therefore are considered true 100% synthetic base oils. Polyalphaolefins provide excellent performance characteristics and have few negative attributes.
PAO base oils are actually similar to mineral oils. The advantage comes from the fact that they are built, rather than extracted and modified, making them more pure. Since they are "man-made", they are tailored to have a controlled molecular structure with predictable properties.
* In 1999 the National Advertising Division (NAD) of the Better Business Bureau, in response to a complaint from ExxonMobil, ruled that Castrol Syntec, which was based on a Group III+ base oil, could be considered "synthetic" because modern oils made using Severe Hydrocracking and Hydro-isomerization technology have most of the same performance features of a "true" Synthetic.
In light of this 'non-binding' ruling, the rest of the major oil manufacturers and blenders decided it was safe to expand that interpretation to cover all Group III base oils and proceeded to do so. It was a low risk marketing decision betting that no one would challenge the move after the NAD ruling, and they were right, no one did.
As a result, the synthetic line was drawn by the oil marketers between Group II+ and Group III base oils. This took pretty much all of the meaning out of the term "synthetic".
However, only Groups IV & V base oils are truly 100% Synthetic.
Note: In some European countries (e.g. Germany), unlike in North America, only Groups IV and V based motor oils can be labelled "Synthetic".
Now that said, what truly matters in the end however, is the quality and performance of the finished blended product. The point is, a motor oil can’t be judged solely by its base oils – you need to take the entire formulation into account (base stock plus additives).
LINK: Base Oil Classification System
Richard
What Does Motor Oil Do?
Modern Motor Oil is a highly specialized product carefully developed by engineers and chemists to perform many essential functions. Today’s oils are complex, chemically engineered compounds that have significantly improved upon refined crude oil.
What does Motor Oil do?
Lubricates / Reduces Friction
While Motor Oil serves a variety of functions, it’s primarily role is to lubricate the engine. Once an engine is started, the oil must circulate promptly and lubricate all moving parts to prevent the metal to-metal contact that would result in wear, scoring, or seizure of the engine.
A reduction in friction leads to less wear on components, easier movement, and reduced energy needs of the system. In fact, some well-designed engine oils can actually increase a car’s fuel economy.
Friction generates heat, so for a lubricant to be successful, it needs to retain its lubricity (slipperiness) even when it gets hot. If a lubricant lacks thermal stability, then it begins to break down when it gets hot, which leads to increased friction.
For oil to be effective it cannot boil away or freeze. In either case, the oil would cease to reduce friction. In the first case, it would simply disappear and leave the moving parts to grind upon one another. In the second case, it would actually increase friction, perhaps to the point of preventing movement altogether.
Motor oils must lubricate and prevent wear in all temperature extremes. Oil that does not flow well in cold temperatures will leave parts of the engine with no protection at start-up (this is when the most metal to metal contact occurs and thus the most wear).
On the other hand, oil that becomes too fluid at high operating temperatures will not be able to maintain an adequate film thickness between moving parts.
Oil flow also refreshes critical additives to the working surfaces. This reserve additive supply includes anti-wear additives, friction modifiers, corrosion inhibitors and others. Lubricant starvation produces elevated heat, which rapidly depletes additives.
Cools
Another essential role of motor oil is to cool the engine. The radiator/antifreeze system is responsible for about 60 percent of the engine cooling that takes place. However, this cools only the upper portion of the engine, including the cylinder heads, cylinder walls and valves. The other 40 percent is cooled by the oil.
Engine heat is created from friction of moving parts and the ignition of fuel inside the cylinder. Oil carries heat away from these hot surfaces as it flows downward and dissipates heat to the surrounding air when it reaches the crankcase.
Keeps Engines Clean
Another important feature of any motor oil related to preventing rust and corrosion is the necessity of keeping engine components clean.
Unburned fuel and soot can mix with water to form sludge and varnish deposits on critical engine parts. Sludge build up may clog oil passages, which reduces oil flow. Varnish build up interferes with proper clearances, restricts oil flow and causes vital engine parts to stick and malfunction. Sludge and varnish can be controlled with the proper additives and can be filtered out of vital engine components.
In performing its lubrication function, some oil must reach the area of the top piston ring in order to lubricate the rings and cylinder walls. However, when exposed to the heat and flame of burning fuel, part of the oil actually boils off.
Modern oils have been chemically engineered to burn as cleanly as possible in order to minimize the harmful deposits left on the walls of the combustion chambers. When excessive deposits build up this can cause ring sticking and breakage, pinging, engine knock or other combustion irregularities that reduce the efficiency and economy of the engine.
Protects Against Rust and Corrosion
For each gallon of fuel burned in an engine, more than one gallon of water is formed. Although most of this water is in vapour form and goes out the exhaust, some condenses on the cylinder walls or escapes past the piston rings and is trapped, at least temporarily, in the crankcase. This occurs most frequently in cold weather before the engine has warmed up.
In addition to water and the by-products from incomplete combustion of the fuel, other corrosive combustion gases also get past the rings and are condensed or dissolved in the engine oil. Add to this the acids formed by the normal oxidation of oil and the potential for rust and corrosive engine deposits becomes significant.
The life of engine parts depends in part on the ability of the motor oil to neutralize these corrosive substances. Oil helps to stop or prevent corrosion by coating components in a thin layer that protects them from exposure to oxygen and other “oxidizers” that can cause chemical reactions to occur that lead to damage to the surface of a material.
The best known example of corrosion is rust. Rust occurs when iron is exposed to oxygen. Rusting can be increased by exposure to water and salt (as anyone who lives in a snowy region where salt is applied to the roads will know).
Thanks to much research, effective oil-soluble chemical compounds have been developed. These are added to motor oils during manufacture to provide vital protection to engine parts.
Neutralizes Acids
Oil’s ability to neutralize acids is expressed by its Base Number (BN) or Total Base Number (TBN).
As oil is used in service, it becomes contaminated with acids, causing the Base Number to drop over time. The BN measures the reserve alkalinity of oil, which is the ability of an alkali to neutralize the effect of acid formation. The greater the number, the greater the amount of acidic by-products the oil can neutralize.
Synthetics have a much higher Base Number retention than petroleum-based formulations. The longer a lubricant can resist turning to acid, the longer it can be used. The BN is contributed by overbase additives such as detergents.
A high Total Base Number (TBN) is particularly important in extended drain interval oils because they neutralize acids, and more of them, for a longer period of time. By using oil analysis, you will be able to track the TBN of your oil and determine how much life is remaining.
Seals
The surfaces of the piston rings, ring grooves and cylinder walls are not completely smooth. They feature microscopic hills and valleys that can reduce engine efficiency by allowing combustion pressure to escape into the low pressure area of the crankcase.
Motor oils must fill in these hills and valleys on ring surfaces and the cylinder walls.
This oil film serves as a seal between the contacting surfaces of the piston rings and interior surfaces of the cylinders to separate the combustion chamber in the cylinder head from the crankcase in the engine block, allowing for maximum combustion pressure.
Permits Easier Starting
The ease of starting an engine depends not only on the condition of the battery, ignition and fuel quality, but also on the flow properties of the motor oil.
If the oil is too viscous (thick) at starting temperatures, it will impose enough drag on the moving parts that the engine cannot be cranked fast enough to start promptly and keep running.
Oil that does not flow well in cold temperatures will leave parts of the engine with no protection at start-up (this is when the most metal to metal contact occurs and thus the most wear).
Since cold temperatures thicken all oils, an oil for winter use must be thin enough to permit adequate cranking speeds at the lowest anticipated temperature. It must also be fluid enough to quickly flow to the bearings to prevent wear.
In addition, the oil must be thick enough, when the engine reaches normal operating temperatures, to provide adequate protection.
Increases Fuel Economy
A final function of motor oil is in increasing fuel economy.
Various additives such as friction modifiers can allow engines to operate at increased levels of efficiency, resulting in better fuel economy for vehicles. A motor oil that has a lower 'hot temperature' viscosity (i.e. a thinner oil) will also offer better fuel economy than a 'thicker' oil due to its lower parasitic drag.
The use of synthetic motor oil can have a profound impact on fuel economy. Industry tests demonstrate an average conservative decrease in fuel consumption by two to five percent by switching to synthetic lubricants. Synthetic lubricants reduce friction and allow engines to use energy more efficiently.
All of these functions, to some extent, can be performed by both mineral and synthetic oils. However, synthetic oils do not contain many of the impurities that mineral oils do allowing them to perform at higher levels in all categories.
LINK: What Does Motor Oil Do?
Pretender
Modern Motor Oil is a highly specialized product carefully developed by engineers and chemists to perform many essential functions. Today’s oils are complex, chemically engineered compounds that have significantly improved upon refined crude oil.
What does Motor Oil do?
- Lubricates / Reduces Friction
- Cools
- Keeps Engines Clean
- Prevents Rust and Corrosion
- Neutralizes Acids
- Seals
- Permits Easier Starting
- Increases Fuel Economy
Lubricates / Reduces Friction
While Motor Oil serves a variety of functions, it’s primarily role is to lubricate the engine. Once an engine is started, the oil must circulate promptly and lubricate all moving parts to prevent the metal to-metal contact that would result in wear, scoring, or seizure of the engine.
A reduction in friction leads to less wear on components, easier movement, and reduced energy needs of the system. In fact, some well-designed engine oils can actually increase a car’s fuel economy.
Friction generates heat, so for a lubricant to be successful, it needs to retain its lubricity (slipperiness) even when it gets hot. If a lubricant lacks thermal stability, then it begins to break down when it gets hot, which leads to increased friction.
For oil to be effective it cannot boil away or freeze. In either case, the oil would cease to reduce friction. In the first case, it would simply disappear and leave the moving parts to grind upon one another. In the second case, it would actually increase friction, perhaps to the point of preventing movement altogether.
Motor oils must lubricate and prevent wear in all temperature extremes. Oil that does not flow well in cold temperatures will leave parts of the engine with no protection at start-up (this is when the most metal to metal contact occurs and thus the most wear).
On the other hand, oil that becomes too fluid at high operating temperatures will not be able to maintain an adequate film thickness between moving parts.
Oil flow also refreshes critical additives to the working surfaces. This reserve additive supply includes anti-wear additives, friction modifiers, corrosion inhibitors and others. Lubricant starvation produces elevated heat, which rapidly depletes additives.
Cools
Another essential role of motor oil is to cool the engine. The radiator/antifreeze system is responsible for about 60 percent of the engine cooling that takes place. However, this cools only the upper portion of the engine, including the cylinder heads, cylinder walls and valves. The other 40 percent is cooled by the oil.
Engine heat is created from friction of moving parts and the ignition of fuel inside the cylinder. Oil carries heat away from these hot surfaces as it flows downward and dissipates heat to the surrounding air when it reaches the crankcase.
Keeps Engines Clean
Another important feature of any motor oil related to preventing rust and corrosion is the necessity of keeping engine components clean.
Unburned fuel and soot can mix with water to form sludge and varnish deposits on critical engine parts. Sludge build up may clog oil passages, which reduces oil flow. Varnish build up interferes with proper clearances, restricts oil flow and causes vital engine parts to stick and malfunction. Sludge and varnish can be controlled with the proper additives and can be filtered out of vital engine components.
In performing its lubrication function, some oil must reach the area of the top piston ring in order to lubricate the rings and cylinder walls. However, when exposed to the heat and flame of burning fuel, part of the oil actually boils off.
Modern oils have been chemically engineered to burn as cleanly as possible in order to minimize the harmful deposits left on the walls of the combustion chambers. When excessive deposits build up this can cause ring sticking and breakage, pinging, engine knock or other combustion irregularities that reduce the efficiency and economy of the engine.
Protects Against Rust and Corrosion
For each gallon of fuel burned in an engine, more than one gallon of water is formed. Although most of this water is in vapour form and goes out the exhaust, some condenses on the cylinder walls or escapes past the piston rings and is trapped, at least temporarily, in the crankcase. This occurs most frequently in cold weather before the engine has warmed up.
In addition to water and the by-products from incomplete combustion of the fuel, other corrosive combustion gases also get past the rings and are condensed or dissolved in the engine oil. Add to this the acids formed by the normal oxidation of oil and the potential for rust and corrosive engine deposits becomes significant.
The life of engine parts depends in part on the ability of the motor oil to neutralize these corrosive substances. Oil helps to stop or prevent corrosion by coating components in a thin layer that protects them from exposure to oxygen and other “oxidizers” that can cause chemical reactions to occur that lead to damage to the surface of a material.
The best known example of corrosion is rust. Rust occurs when iron is exposed to oxygen. Rusting can be increased by exposure to water and salt (as anyone who lives in a snowy region where salt is applied to the roads will know).
Thanks to much research, effective oil-soluble chemical compounds have been developed. These are added to motor oils during manufacture to provide vital protection to engine parts.
Neutralizes Acids
Oil’s ability to neutralize acids is expressed by its Base Number (BN) or Total Base Number (TBN).
As oil is used in service, it becomes contaminated with acids, causing the Base Number to drop over time. The BN measures the reserve alkalinity of oil, which is the ability of an alkali to neutralize the effect of acid formation. The greater the number, the greater the amount of acidic by-products the oil can neutralize.
Synthetics have a much higher Base Number retention than petroleum-based formulations. The longer a lubricant can resist turning to acid, the longer it can be used. The BN is contributed by overbase additives such as detergents.
A high Total Base Number (TBN) is particularly important in extended drain interval oils because they neutralize acids, and more of them, for a longer period of time. By using oil analysis, you will be able to track the TBN of your oil and determine how much life is remaining.
Seals
The surfaces of the piston rings, ring grooves and cylinder walls are not completely smooth. They feature microscopic hills and valleys that can reduce engine efficiency by allowing combustion pressure to escape into the low pressure area of the crankcase.
Motor oils must fill in these hills and valleys on ring surfaces and the cylinder walls.
This oil film serves as a seal between the contacting surfaces of the piston rings and interior surfaces of the cylinders to separate the combustion chamber in the cylinder head from the crankcase in the engine block, allowing for maximum combustion pressure.
Permits Easier Starting
The ease of starting an engine depends not only on the condition of the battery, ignition and fuel quality, but also on the flow properties of the motor oil.
If the oil is too viscous (thick) at starting temperatures, it will impose enough drag on the moving parts that the engine cannot be cranked fast enough to start promptly and keep running.
Oil that does not flow well in cold temperatures will leave parts of the engine with no protection at start-up (this is when the most metal to metal contact occurs and thus the most wear).
Since cold temperatures thicken all oils, an oil for winter use must be thin enough to permit adequate cranking speeds at the lowest anticipated temperature. It must also be fluid enough to quickly flow to the bearings to prevent wear.
In addition, the oil must be thick enough, when the engine reaches normal operating temperatures, to provide adequate protection.
Increases Fuel Economy
A final function of motor oil is in increasing fuel economy.
Various additives such as friction modifiers can allow engines to operate at increased levels of efficiency, resulting in better fuel economy for vehicles. A motor oil that has a lower 'hot temperature' viscosity (i.e. a thinner oil) will also offer better fuel economy than a 'thicker' oil due to its lower parasitic drag.
The use of synthetic motor oil can have a profound impact on fuel economy. Industry tests demonstrate an average conservative decrease in fuel consumption by two to five percent by switching to synthetic lubricants. Synthetic lubricants reduce friction and allow engines to use energy more efficiently.
All of these functions, to some extent, can be performed by both mineral and synthetic oils. However, synthetic oils do not contain many of the impurities that mineral oils do allowing them to perform at higher levels in all categories.
LINK: What Does Motor Oil Do?
Pretender
Why Does Oil Need To Be Changed?
It is common knowledge that, at some point, engine oil must be changed. It's something that is preached relentlessly to vehicle owners by vehicle manufacturers, quick lubes and oil companies. But consumers are widely unaware of what exactly makes oil changes necessary.
Motor Oil is not like a fine wine that gets better over time. Instead, it ages at a rate that is influenced by engine age, driving conditions, fuel quality, motor oil quality and climate. If not changed in time, your oil will degrade and fail to protect your engine.
Many factors contribute to a motor oil's demise, but it is essentially the accumulation of contaminants in the oil and chemical changes in the oil itself that make a motor oil unfit for further service. With time, it is inevitable that the oil will be contaminated by dirt or sludge, or succumb to the extreme pressures or temperatures found inside an engine.
In order to understand why oil needs to be changed, we must first look at what causes motor oil to deteriorate, eventually becoming unfit for service and continued use.
Several factors cause deterioration of the oil and prevent it from doing the job of lubricating and cooling engine parts:
Abrasives
Dust and Dirt
The design limitations of air cleaners, some oil fill caps and crankcase ventilation systems allow a certain level of dust and dirt into the engine, while leaks in the intake system can permit unfiltered air to enter the engine. Particles of dust and dirt are circulated through the engine by the oil increasing wear rates.
It is well-known that contaminants in engine oils contribute to excessive oil consumption. Particle contamination is one of the leading causes of poor equipment reliability. Excessive particle ingression can result in valve stiction and seal wear, both of which can lead to progressive or sudden fluid loss.
Metal Particles
Normal wear of engine parts produces very small metal particles that are picked up and circulated by the oil. These metal particles increase wear rates and generate larger, even more abrasive metal particles that are then circulated through the engine by the oil.
Wear particles cause abrasive wear, particularly between rings and cylinders, leading to excessive blow-by. Blow-by, of course, allows oil to pass from the sump into the combustion chamber where it burns and leaves the engine through the tail pipe.
Coming in from the other direction, blow-by increases soot loading in the oil, rendering the antiwear additives less effective. In turn, this increases ring-to-cylinder wear, resulting in yet more blow-by and creating a vicious cycle of lubricant degradation and engine wear.
While oil filters help keep these particles at a minimum, they can’t remove them entirely.
Combustion By-products
Water
It is important to remember that combustion produces water vapor in your engine – more water than the fuel consumed. When engine temperatures are high, most of the water goes out the tailpipe, but if the engine is cool, much of it may condense in the crankcase where it leads to the formation sludge, rust and corrosion.
Sludge deposits collect on oil pump screens, limiting the flow of oil to vital engine parts and resulting in rapid and destructive wear.
Free and emulsified water is harmful to the oil and the engine especially for short-trip drivers. Water condensation may be even more acute if your engine has the flexible fuel vehicle (FFV) option and you are burning an alcohol-gasoline fuel blend.
Acids
As oil ages and oxidises, more and more acids are generated and start to build up, with the end result being an increase in the Total Acid Number (TAN). A high acid number represents the potential for corrosion, rust and oxidation. It can also be a signal to perform an oil change.
Just like with most chemical reactions, base oil oxidation is accelerated by heat and pressure. It is no different than other commonly encountered oxidation reactions, such as rusting.
Oxidation is a degradation process that occurs when atmospheric oxygen reacts with organic molecules. Just like the effects that rusting and other corrosive processes have on metal substrates, oil oxidation results in a catastrophic and permanent chemical change to the base oil molecules.
The net effect of prolonged oxidation is that the oil becomes acidic, causing corrosion, while an increase in viscosity occurs. Oxidation will generally happen at a slow rate under optimum conditions; however, as the health of the oil decreases, the rate of degradation will increase.
There are several other factors that, if not controlled, can lead to increased rates of oxidation, including heat, air, water and metallic particles.
During combustion, a low-quality fuel with high sulfur content can produce sulfuric acid, which attacks the oil and causes a drop in the Total Base Number (TBN) which reflects the oil’s ability to neutralize acids.
Synthetic-based formulations have much higher Base Number (BN) retention than petroleum-based formulations. The longer a lubricant can resist turning to acid, the longer it can be used.
Soot and Carbon
Incomplete combustion produces soot, carbon and other deposit-forming materials.
An engine running too “rich” (with too much fuel) increases contaminant levels. Light-load, low-speed gasoline engine operation, as well as high-load, low-speed diesel engine operation increase levels of these combustion by-products.
Dilution of the Oil
In certain cases, the oil level may have risen since the last time you checked.
This could be due to condensed water (from combustion), condensed fuel or a coolant leak - all are causes for concern. Although this can be only a minor problem when engine operation is at high-speed or high-temperatures, it can be a significant problem in vehicles consistently used for short-trips.
When an engine is started or running abnormally, some unburned fuel is deposited on cylinder walls, leaking past the rings and into the crankcase. Fuel-diluted motor oil (from blow-by or leakage) can substantially reduce oil viscosity and thin additive concentration.
Fuel dilution also decreases oil film strength and increases oil consumption.
Depletion of Additives
When Motor Oil is blended, many chemicals (additives) are added to the oil. Additives impart new characteristics to the oil, or improve existing characteristics, enabling it to function in a desired manner when used to lubricate an engine. Additives improve the overall performance of the fluid.
Additives are used to enhance the beneficial properties of the base oil, helping it stand up to extreme operating environments, and make up for its deficiencies. Even the best base oil would not be able to protect as well against the effects of heat, shearing forces, chemical and water dilution, corrosion and wear particles. In short, additives make good base oils even better.
The various chemicals that comprise the additive system help modern Lubricants meet the increasing demands of today's high-tech engines. For passenger car motor oils, base oil makes up 70 to 80 percent of the final product; the other 20 to 30 percent is comprised of additive chemistry.
The more these additives become depleted, the less protection they provide. It’s also important to note that additives are sacrificial. Once they are gone, they’re gone.
Extreme Heat
Today's engines are running hotter than ever. More horsepower, turbo chargers and aerodynamic styling have created extremely hot environments that receive less cooling from outside air. High heat leads to oil oxidation, deposits and thickening in conventional oils.
Because they are made from impure, irregular molecules, conventional motor oils are more susceptible to the effects of heat.
The small, light molecules in conventional oil tend to evaporate as the oil is heated, leaving large, heavy molecules behind and leading to oil consumption and an increase in the oil's viscosity. If those large, heavy molecules are chemically unstable, they may also break-down and form deposits on component surfaces, further inhibiting the release of heat into the oil stream.
Even in relatively mild temperatures, oxygen works to break down some of the chemicals in conventional lubricants. The extreme heat in engines actually promotes oxidation. When conventional oil contaminants break down, they coat components with varnish, deposits and sludge and leave the lubricant thick, hard to pump and with very poor heat transfer ability.
LINK: Why Does Oil Need To Be Changed?
Richard
It is common knowledge that, at some point, engine oil must be changed. It's something that is preached relentlessly to vehicle owners by vehicle manufacturers, quick lubes and oil companies. But consumers are widely unaware of what exactly makes oil changes necessary.
Motor Oil is not like a fine wine that gets better over time. Instead, it ages at a rate that is influenced by engine age, driving conditions, fuel quality, motor oil quality and climate. If not changed in time, your oil will degrade and fail to protect your engine.
Many factors contribute to a motor oil's demise, but it is essentially the accumulation of contaminants in the oil and chemical changes in the oil itself that make a motor oil unfit for further service. With time, it is inevitable that the oil will be contaminated by dirt or sludge, or succumb to the extreme pressures or temperatures found inside an engine.
In order to understand why oil needs to be changed, we must first look at what causes motor oil to deteriorate, eventually becoming unfit for service and continued use.
Several factors cause deterioration of the oil and prevent it from doing the job of lubricating and cooling engine parts:
- The accumulation of contaminants in the oil such as:
- Abrasives (Dust and Dirt; Metal Particles)
- Combustion By-products (Water; Acids; Soot and Carbon) - Chemical changes in the oil itself caused by:
- Dilution of the oil
- Depletion of additives
- Extreme Heat
Abrasives
Dust and Dirt
The design limitations of air cleaners, some oil fill caps and crankcase ventilation systems allow a certain level of dust and dirt into the engine, while leaks in the intake system can permit unfiltered air to enter the engine. Particles of dust and dirt are circulated through the engine by the oil increasing wear rates.
It is well-known that contaminants in engine oils contribute to excessive oil consumption. Particle contamination is one of the leading causes of poor equipment reliability. Excessive particle ingression can result in valve stiction and seal wear, both of which can lead to progressive or sudden fluid loss.
Metal Particles
Normal wear of engine parts produces very small metal particles that are picked up and circulated by the oil. These metal particles increase wear rates and generate larger, even more abrasive metal particles that are then circulated through the engine by the oil.
Wear particles cause abrasive wear, particularly between rings and cylinders, leading to excessive blow-by. Blow-by, of course, allows oil to pass from the sump into the combustion chamber where it burns and leaves the engine through the tail pipe.
Coming in from the other direction, blow-by increases soot loading in the oil, rendering the antiwear additives less effective. In turn, this increases ring-to-cylinder wear, resulting in yet more blow-by and creating a vicious cycle of lubricant degradation and engine wear.
While oil filters help keep these particles at a minimum, they can’t remove them entirely.
Combustion By-products
Water
It is important to remember that combustion produces water vapor in your engine – more water than the fuel consumed. When engine temperatures are high, most of the water goes out the tailpipe, but if the engine is cool, much of it may condense in the crankcase where it leads to the formation sludge, rust and corrosion.
Sludge deposits collect on oil pump screens, limiting the flow of oil to vital engine parts and resulting in rapid and destructive wear.
Free and emulsified water is harmful to the oil and the engine especially for short-trip drivers. Water condensation may be even more acute if your engine has the flexible fuel vehicle (FFV) option and you are burning an alcohol-gasoline fuel blend.
Acids
As oil ages and oxidises, more and more acids are generated and start to build up, with the end result being an increase in the Total Acid Number (TAN). A high acid number represents the potential for corrosion, rust and oxidation. It can also be a signal to perform an oil change.
Just like with most chemical reactions, base oil oxidation is accelerated by heat and pressure. It is no different than other commonly encountered oxidation reactions, such as rusting.
Oxidation is a degradation process that occurs when atmospheric oxygen reacts with organic molecules. Just like the effects that rusting and other corrosive processes have on metal substrates, oil oxidation results in a catastrophic and permanent chemical change to the base oil molecules.
The net effect of prolonged oxidation is that the oil becomes acidic, causing corrosion, while an increase in viscosity occurs. Oxidation will generally happen at a slow rate under optimum conditions; however, as the health of the oil decreases, the rate of degradation will increase.
There are several other factors that, if not controlled, can lead to increased rates of oxidation, including heat, air, water and metallic particles.
During combustion, a low-quality fuel with high sulfur content can produce sulfuric acid, which attacks the oil and causes a drop in the Total Base Number (TBN) which reflects the oil’s ability to neutralize acids.
Synthetic-based formulations have much higher Base Number (BN) retention than petroleum-based formulations. The longer a lubricant can resist turning to acid, the longer it can be used.
Soot and Carbon
Incomplete combustion produces soot, carbon and other deposit-forming materials.
An engine running too “rich” (with too much fuel) increases contaminant levels. Light-load, low-speed gasoline engine operation, as well as high-load, low-speed diesel engine operation increase levels of these combustion by-products.
Dilution of the Oil
In certain cases, the oil level may have risen since the last time you checked.
This could be due to condensed water (from combustion), condensed fuel or a coolant leak - all are causes for concern. Although this can be only a minor problem when engine operation is at high-speed or high-temperatures, it can be a significant problem in vehicles consistently used for short-trips.
When an engine is started or running abnormally, some unburned fuel is deposited on cylinder walls, leaking past the rings and into the crankcase. Fuel-diluted motor oil (from blow-by or leakage) can substantially reduce oil viscosity and thin additive concentration.
Fuel dilution also decreases oil film strength and increases oil consumption.
Depletion of Additives
When Motor Oil is blended, many chemicals (additives) are added to the oil. Additives impart new characteristics to the oil, or improve existing characteristics, enabling it to function in a desired manner when used to lubricate an engine. Additives improve the overall performance of the fluid.
Additives are used to enhance the beneficial properties of the base oil, helping it stand up to extreme operating environments, and make up for its deficiencies. Even the best base oil would not be able to protect as well against the effects of heat, shearing forces, chemical and water dilution, corrosion and wear particles. In short, additives make good base oils even better.
The various chemicals that comprise the additive system help modern Lubricants meet the increasing demands of today's high-tech engines. For passenger car motor oils, base oil makes up 70 to 80 percent of the final product; the other 20 to 30 percent is comprised of additive chemistry.
The more these additives become depleted, the less protection they provide. It’s also important to note that additives are sacrificial. Once they are gone, they’re gone.
Extreme Heat
Today's engines are running hotter than ever. More horsepower, turbo chargers and aerodynamic styling have created extremely hot environments that receive less cooling from outside air. High heat leads to oil oxidation, deposits and thickening in conventional oils.
Because they are made from impure, irregular molecules, conventional motor oils are more susceptible to the effects of heat.
The small, light molecules in conventional oil tend to evaporate as the oil is heated, leaving large, heavy molecules behind and leading to oil consumption and an increase in the oil's viscosity. If those large, heavy molecules are chemically unstable, they may also break-down and form deposits on component surfaces, further inhibiting the release of heat into the oil stream.
Even in relatively mild temperatures, oxygen works to break down some of the chemicals in conventional lubricants. The extreme heat in engines actually promotes oxidation. When conventional oil contaminants break down, they coat components with varnish, deposits and sludge and leave the lubricant thick, hard to pump and with very poor heat transfer ability.
LINK: Why Does Oil Need To Be Changed?
Richard
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