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KIA Rio5 2012 EX
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Discussion Starter #1 (Edited)
Mileage Information on Trip Computer SUCKS

I have had a considerable amount of time (about 20k miles) to test the so called 30/40 (now 28/36) MPG ratings and I have come to the conclusion that the trip computer spews lies.

No joke here... there is at least a 10mpg difference between what the trip computer reports and what I get in Torque using my bluetooth ODBII reader. You can also test this by using the Trip counter and manually calculating MPG by hand.

Using the on-board trip computer, ECO mode and cruise control on the highway I can get about 45-50mpg at ~45mph, about 40-45mpg at ~60mph and about 35-40mpg at ~75mph. However using Torque reveals that there is only a minimal difference between speeds and the actual mpg ratings are more like 28-32mpg at any speed 45-75mph. When I made the same calculations using my trip counter manually the mpg ratings tended to match up with the measurements made in Torque.

What does all this mean? The trip computer LIES! Whenever you look at your mpg average just subtract 10mpg for the true mileage. The computer is also subject to heavy bias based on how you drive the car immediately after resetting. If you change your habits you are not likely to see a huge change in the mpg average on the trip computer.

It makes me sick to think I bragged to all my friends my 45mpg average highway mileage when I was actually getting about 32mpg. Makes you wonder if they used the trip computer when they advertised 30/40 mpg ratings...

I get that the mpg rebate is supposed to make things better but the fact is that it doesn't. On top of things I have only received a single mileage rebate (follow up rebates are not available yet...) The Rio5 is a damn sexy car and I am still loving my vehicle but I chose this over the Honda Insight which gets 40/40mpg consistently and is about the same price in my area. Not to mention that compared to the insight the value of my car is significantly less. Nobody is going to want a 28/36mpg vehicle (which is actually more like 24/32) when they can find cheaper vehicles of the same year or earlier which can actually achieve 40mpg.

And don't even get me started on RIO city mileage. I'm assuming there is no way to fix the trip computer unless KIA officially releases a firmware fix for the trip computer. Any thoughts? Sorry about the wall of text but there plenty to be said about how KIA's crappy mileage calculations have really screwed things up.

EDIT:

Here are my torque readings with the raw measurements and MPG calculations.
https://docs.google.com/spreadsheet/pub?key=0Aj51NGa5YbEFdE5mVTNidmhNZDJPS2NwcnhXQjVsamc&single=true&gid=0&output=html
They show my highway average for 45 minutes to be about 32.2mpg. This is same trip that the computer reported 45mpg...


UPDATE:

Okay so I did some digging around and I called KIA customer service about the mileage correction and they refused to do any type of investigation of illegitimate mileage claims based on the ground that the "EPA has set the mpg ratings on my vehicle".

So I took a brand new Rio5 2012 Hatchback for a test drive with torque and drove the same trip in both cars. I adjusted both cars logs and removed all idling to make it easier to compare actual fuel usage. In the new car which was cold-started I actually got worse mileage than driving my own vehicle (which was warmed up from the drive).

Here are the logs for the new vehicle (27MPG):
https://docs.google.com/spreadsheet/...mc&output=html

And for my "slightly used" vehicle (32MPG):
https://docs.google.com/spreadsheet/...UE&output=html

Sorry wish the test drive was a bit longer :\
 

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2013 Rio SX Hatchback
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417 Posts
10mpg difference may be over stating it. Well in my case anyway. I'm finding only about 0.5 to 1.0 L/100km difference. Which is around 3mpg.

As for the Honda Insight......yuk. Looks way too much like the Prius. Mileage may not be as good but the Rio is by far a better looking car.
 

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2020 Kia Sorento EX+
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393 Posts
Over 33 fillups I am averaging 0.55 l/100km optimistic by the computer, min = -0.17 L/100 km and max was 1.7 L/100km, but that was an outlier, max typical is just under 1.0
 

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Cerato S Hatch Auto
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1,236 Posts
I didn't think anyone took the trip computer mileage seriously. One of my cars is consistently 10% optimistic on the readout, but it's still a useful guide. It does give a realistic DTE reading, however.

Considering that fuel measurements are rather tricky, a rough guide to the actual usage is the best you'll get, unless you're lucky and it's been properly calibrated. A read-out from the ECM giving fuel injection data will give an approximation to fuel usage, but this depends on constant fuel pressure. Maybe some cars have traditional flow meters in the fuel line; another approach would be a very accurate gauge in the fuel tank, but they are usually only accurate enough to give a reasonably warning of DTE.

Anyone know exactly what KIA uses for sensing fuel usage?
 

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2013 Kia Rio EX Sedan 2012 Acura TL Advanced, 2001 Ford Expedition Eddie Bauer
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26 Posts
Yes, my computer lies but just a little bit. About 1 mpg off. I'm getting 33 mpg city/hwy. I was getting 10-11 mpg driving my Ford Expedition full time, so I'll take 33 mpg. The fuel savings is paying for the Kia.
 

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2012 Kia Rio 5-Door LX
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301 Posts
Mine is about 2.5 to 3 miles off and I'm averaging around 33.5 with 14k miles on it... and it is still improving. I was also mislead by the trip computer initially but that lasted about... 1 tank fill. I know that the manual calculation is more accurate than the computer.
 

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KIA Rio5 2012 EX
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Discussion Starter #7 (Edited)
I didn't think anyone took the trip computer mileage seriously. One of my cars is consistently 10% optimistic on the readout, but it's still a useful guide. It does give a realistic DTE reading, however.

Considering that fuel measurements are rather tricky, a rough guide to the actual usage is the best you'll get, unless you're lucky and it's been properly calibrated. A read-out from the ECM giving fuel injection data will give an approximation to fuel usage, but this depends on constant fuel pressure. Maybe some cars have traditional flow meters in the fuel line; another approach would be a very accurate gauge in the fuel tank, but they are usually only accurate enough to give a reasonably warning of DTE.

Anyone know exactly what KIA uses for sensing fuel usage?
Torque can access the fuel usage sensor as well as a range of other sensors. I will post my torque usage here in a bit. It can log the difference between speed and mpg during the course of my trip. I also have another theory that maybe cruise control may be causing the overoptimistic data. Because of the implied improvement in mpg using the trip computer I always use cruise control when it is safe. One thing I noticed is that cruise control doesn't really increase my torque mpg readings like it does on my trip computer.
 

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14 Forte SX Koupe,15 Soul EX,58 & 90 Rolls Royces,92 Mercedes 500SL
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I agree with marleyfan61 & lordhelmet.I find it's out about .5 ltrs/100km out.Speedometers are usually out that much so it doesn't bother me.Maybe the U.S. cars have more inaccuracies as us Canucks see to all agree;).
 

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former owner of a 2016 Soul SX 2.0L - Caribbean Blue
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I agree with rroyce46, even on my Soul its not out by much compared to manual calculation in fact sometimes is optimistic and other times its pessimistic but not by a lot so overall I consider it pretty accurate, certainly not going to loose sleep over it.

I would imagine that if you reset it while driving and give it a km or two to adjust, that figure is probably pretty accurate at that point. When you fill up probably causes most of the variation due to various pumps shut off slightly differently.
 

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Kia Rio 2013 S 1.4
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I have had a considerable amount of time (about 20k miles) to test the so called 30/40 (now 28/36) MPG ratings and I have come to the conclusion that the trip computer spews lies.

No joke here... there is at least a 10mpg difference between what the trip computer reports and what I get in Torque using my bluetooth ODBII reader. You can also test this by using the Trip counter and manually calculating MPG by hand.

Using the on-board trip computer, ECO mode and cruise control on the highway I can get about 45-50mpg at ~45mph, about 40-45mpg at ~60mph and about 35-40mpg at ~75mph. However using Torque reveals that there is only a minimal difference between speeds and the actual mpg ratings are more like 28-32mpg at any speed 45-75mph. When I made the same calculations using my trip counter manually the mpg ratings tended to match up with the measurements made in Torque.

What does all this mean? The trip computer LIES! Whenever you look at your mpg average just subtract 10mpg for the true mileage. The computer is also subject to heavy bias based on how you drive the car immediately after resetting. If you change your habits you are not likely to see a huge change in the mpg average on the trip computer.

It makes me sick to think I bragged to all my friends my 45mpg average highway mileage when I was actually getting about 32mpg. Makes you wonder if they used the trip computer when they advertised 30/40 mpg ratings...

I get that the mpg rebate is supposed to make things better but the fact is that it doesn't. On top of things I have only received a single mileage rebate (follow up rebates are not available yet...) The Rio5 is a damn sexy car and I am still loving my vehicle but I chose this over the Honda Insight which gets 40/40mpg consistently and is about the same price in my area. Not to mention that compared to the insight the value of my car is significantly less. Nobody is going to want a 28/36mpg vehicle when they can find cheaper vehicles of the same year or earlier which can actually achieve 40mpg.

And don't even get me started on RIO city mileage. I'm assuming there is no way to fix the trip computer unless KIA officially releases a firmware fix for the trip computer. Any thoughts? Sorry about the wall of text but there plenty to be said about how KIA's crappy mileage calculations have really screwed things up.

After reading all the post I would suggest you to go to the dealer and require to have a sensors check or a car's computer check, something is really wrong with your mpg
 

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06 Sedona LX, 06 Sedona EX, 14 Forte EX, 11 Sportage EX, 11 Forte 5-door SX, 15 K900 VIP+
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I know this is an apples to oranges comparison, but my Sedona (06) is usually correct within .2-.4 MPG and my Amanti (09) is typically .7-.9 MPG off. Same engine, tuned differently, but I have always wondered how they can read so different.
 

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'12 Rio SLS, '13 XR6 Turbo, '15 XR8 S/C
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995 Posts
i can tell you that from the start my SLS read 1L/100 out as far as fuel economy went. Actual (worked out) figures would be about 8L/100 and the trip computer would say 7L/100. Now that i run it on premium (for another issue) and it has over 21,000KM on it, the readings from the trip computer and the manually worked out figures are almost identical. So to say for everyone to subtract 10MPG from their computer readout is a fallacy, you obviously have an issue with your car which needs fixing.

To illustrate my point, have a look at this graph. The grey line on the graph is indicating what the trip computer said at the fill, while the white line represents what the actual worked out economy was. Sometimes the grey line (trip computer) even says i got worse economy than i actually did, as you can see on the graph. Courtesy of Road Trip on iOS, buy it, it's good.

 

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NA V, K3
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It's been a pretty well known fact that the trip computers give a better than actual reading, not just for Hyundai/Kia. For that reason, you always have to calculate manually for the best results.
 

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2013 Kia Rio 5 SX UVO, 2012 Cadillac Escalade Ultra Luxury
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For anyone doing this as well.. make sure you are averaging both ways THE SAME.... ie, if you fill up and want to average that specific tank, then reset the KIA cluster when you fill up. If you want to average over 5 tanks, then dont reset the cluster.
 

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2013 Rio SX Hatchback
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Here are my torque readings for highway driving:

https://docs.google.com/spreadsheet/pub?key=0Aj51NGa5YbEFdE5mVTNidmhNZDJPS2NwcnhXQjVsamc&single=true&gid=0&output=html

They show my highway average for 45 minutes to be about 32.2mpg. This is same trip that the computer reported 45mpg... gonna try again without cruise control and see what happens.
If you're getting that big of a difference then there is clearly a problem with your trip computer. That much of a discrepency is clearly far from typical. Take it to the dealer.

They are more likely to respond favorably if you approach it as a trip computer accuracy issue rather than a complaint about fuel economy. A re-flash may fix it.
 

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former owner of a 2016 Soul SX 2.0L - Caribbean Blue
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For anyone doing this as well.. make sure you are averaging both ways THE SAME.... ie, if you fill up and want to average that specific tank, then reset the KIA cluster when you fill up. If you want to average over 5 tanks, then dont reset the cluster.
unless the Rio is different, but on my Soul, it automatically resets when you fill up and pull away from the pumps, you don't have any choice.
 

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2013 Soul+ Shadow, 1970 Opel GT 1.9 CIH 4M
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Not So Bad

Over the past 4200 miles I have kept very accurate and consistent gas logs. I have found my trip computer to be 1.7 MPG optimistic. I can definitely live with that! The more I drive this car, the more I appreciate it. Now if I could only eliminate that intermittent rattle in the passenger side dash I would have the perfect car :rolleyes:
 

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2013 Kia Rio 5 SX UVO, 2012 Cadillac Escalade Ultra Luxury
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116 Posts
unless the Rio is different, but on my Soul, it automatically resets when you fill up and pull away from the pumps, you don't have any choice.
Oh, I never knew that if that's the case.... i have been resetting everytime anyways.. iwill have to try that out.

Learned something new today. check.
 
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