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2012 Rio EX Sedan UVO Auto/Tanzanite blue/tinted windows/Vent visors
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Discussion Starter #1
Hello, does the size of the tires have some kind of influence on the fuel economy on the Rio. My tires are Hankook Optimo H426 195/55R16. I was told the 17 inch tires of the SX provide a better handling but a little less fuel economy and the best economy comes with the 15 inch. Some clues?
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2013 Rio5 EX w/ Convenience & ISG
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Arguable. The 15 and the 17 have the same overall tire diameter so the Rotations Per Mile (RPM) will be the same +/- 1% so no great savings there in engine speed.

The 17's 205mm wide tread will cost some in road resistance but the US Government (yes, the US Gov't so believe it) declares both 185s and 205s tired cars will equally get 40mpg highway.

However it'll be in the tire makeup itself. I'm sure injection-molded tires like Big Wheels that will have "970" on tire wear will get the greatest economy but poorest 'stickiness'.

I traded in the MH25 for a softer set of Goodyear Assurance Comfortred Touring that I'm sure will cost me 1-2 mpg but at least I'll stay on the road come bad weather and not shatter my teeth on road joints around here.
 

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2012 Rio5 EX 6spd
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Although the OD stays more or less the same, weight goes up, fuel economy and performance (acceleration) will go down.

Car and Driver did a test awhile back, comparing 15" - 19" rims using the same tires. The best fuel economy and performance came from the 15" steel wheels. Grip went up to a point, I think after the 17" it started to go down again.

As far as the EPA testing goes, I don't think they have to test every permutation of the vehicle for the EPA ratings. I could be wrong about that though.

Thanks

Brian
 

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10 Optima LX, 07 Rondo EX, 89 Chevy C1500
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When it come to tires/wheels and fuel economy, light and narrow will do better, because there is less rolling resistance. There is less mass , which makes them easier to spin, and narrow means a small contact patch, which is less drag.
 

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14 Forte SX Koupe,15 Soul EX,58 & 90 Rolls Royces,92 Mercedes 500SL
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Would be curious to know if we are talking 1,2,3 or 4 mpg difference between 15 inch steelies vs 16 or 17 inch alloys & the weight difference.Steelies are usually quite heavy.Also the 185 vs 205 tyres would increase the drag factor by 1.6 inches width for the 2 front tyres. My SX Sedan has seventeens & I am one of the few who seem to feel the mpg or litres per 100 km is great:D. Government fuel economy figures are quite realistic in view of the fact they are not done on the road but in a laboratory or rolling road.Another variable is that the Rio Specs in the Canadian brochure state that only the 15 inchers are "low rolling resistance" tyres.
 

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2012 Rio5 EX 6spd
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I'll have to try and find the article.

I don't think it was a huge difference in MPG, just a measured drop, and in acceleration as well.

I'll see if I can find it...

Thanks

Brian
 

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2012 Rio5 EX 6spd
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Here's a link to it:

Effects of Upsized Wheels and Tires Tested - Tech Dept. - Car and Driver

Grip actually was best at 18", not 17" as I had thought. Tread compound is apparently stickier with the 18 and 19". Quite the difference in weight between the 15" steel wheels and even the 16" alloys. 14lbs heavier for the 19"!

I too have been getting excellent mileage. I have the 16" alloy wheels, and my best tank was 5.88 l/100km, and I am regularly in the low 6's.

Thanks

Brian
 

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Thanks brianl. Car & driver quotes .5 MPG difference going from 15 to 17 inch & 0-60 MPH slower by .2 seconds. I can live with both those numbers just for the improved cornering & looks!:D
 

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2012 Rio EX Sedan UVO Auto/Tanzanite blue/tinted windows/Vent visors
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Discussion Starter #9
Gee, I'm flabbergasted

Here's a link to it:

Effects of Upsized Wheels and Tires Tested - Tech Dept. - Car and Driver

Grip actually was best at 18", not 17" as I had thought. Tread compound is apparently stickier with the 18 and 19". Quite the difference in weight between the 15" steel wheels and even the 16" alloys. 14lbs heavier for the 19"!

I too have been getting excellent mileage. I have the 16" alloy wheels, and my best tank was 5.88 l/100km, and I am regularly in the low 6's.

Thanks

Brian
Hello and thanks for all the good information. Brian, may I ask you how the .... you can achieve this excellent mileage with your Rio? Please, please gimme some advices, some hints, some tricks. I too have the 16" alloys and no way my Rio can do better than 7.5L/100 and God knows I drive it like a grand'ma would. Actually, I have no fun at all driving this car. I'm too much focused on fuel economy. In a few days I will have to fill up and as I see it, it will be an all time low since the little time I have the car (4 months): I'll be lucky if the Trip A shows over 400 km. For me, it's back to my Neon time and its fuelalcoholism and its 8.5-9.1L/100km. OK, I'm ready...Tell me you only do highways please!!!
 

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12 RIO 5 SX, 07 VW Passat 2.0L turbo 1952 Siata Diana
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The Tire rack has excellent charts showing the rolling circumference of all tire sizes.
Changing tire size has the same effect as changing the Axel Ratio. The higher the Axel Ratio the better acceleration, but worst fuel economy. Ther are other variables, but this is a good general rule.
 

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Accord, stick
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Hello and thanks for all the good information. Brian, may I ask you how the .... you can achieve this excellent mileage with your Rio? Please, please gimme some advices, some hints, some tricks. I too have the 16" alloys and no way my Rio can do better than 7.5L/100 and God knows I drive it like a grand'ma would. Actually, I have no fun at all driving this car. I'm too much focused on fuel economy. In a few days I will have to fill up and as I see it, it will be an all time low since the little time I have the car (4 months): I'll be lucky if the Trip A shows over 400 km. For me, it's back to my Neon time and its fuelalcoholism and its 8.5-9.1L/100km. OK, I'm ready...Tell me you only do highways please!!!
That (5.88) or even less is what I would expect from such small car (engine wise). I filled last night and calculation shows 6.49L/100km. Bigger engine, heavier car, stick, leisurely driving (some call it 'like grandma' I call it SMART driving - no rabbit accelerations, no 'bicycle' driving (gas/brake only nothing in between), coasting to stop, timing lights, etc. I hear some call it hypermiling but for me that was always SMART driving from day one I got license...).
 

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2012 Rio5 EX 6spd
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Hello and thanks for all the good information. Brian, may I ask you how the .... you can achieve this excellent mileage with your Rio? Please, please gimme some advices, some hints, some tricks. I too have the 16" alloys and no way my Rio can do better than 7.5L/100 and God knows I drive it like a grand'ma would. Actually, I have no fun at all driving this car. I'm too much focused on fuel economy. In a few days I will have to fill up and as I see it, it will be an all time low since the little time I have the car (4 months): I'll be lucky if the Trip A shows over 400 km. For me, it's back to my Neon time and its fuelalcoholism and its 8.5-9.1L/100km. OK, I'm ready...Tell me you only do highways please!!!
Yes, about 95% highway driving. While I've been keeping my terminal velocity in check, I do accelerate 'briskly'. I look ahead and drive accordingly. If my next light is going to change before I get through it, I close the throttle and coast with the objective of hitting the light as it turns green again, not stopping at all. Obviously this can't always happen, in which I will still coast to the light with the objective of minimizing stopped time. I won't hold up traffic though.

As strange as it sounds, drive as much as possible with the throttle closed. If you're in gear and coasting fast enough with the throttle closed, you will engage your DFCO (deceleration fuel cut-off), and your injectors won't fire. Doing this can have a huge impact on your city mileage (and also highway, it's just harder to exploit and maintain highway speeds).

I'm just under 15,000 km, average is 6.77 l/100km, and that is trending downwards.

Thanks

Brian
 

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2012 Rio EX Sedan UVO Auto/Tanzanite blue/tinted windows/Vent visors
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Discussion Starter #13
Yes, about 95% highway driving. While I've been keeping my terminal velocity in check, I do accelerate 'briskly'. I look ahead and drive accordingly. If my next light is going to change before I get through it, I close the throttle and coast with the objective of hitting the light as it turns green again, not stopping at all. Obviously this can't always happen, in which I will still coast to the light with the objective of minimizing stopped time. I won't hold up traffic though.

As strange as it sounds, drive as much as possible with the throttle closed. If you're in gear and coasting fast enough with the throttle closed, you will engage your DFCO (deceleration fuel cut-off), and your injectors won't fire. Doing this can have a huge impact on your city mileage (and also highway, it's just harder to exploit and maintain highway speeds).

I'm just under 15,000 km, average is 6.77 l/100km, and that is trending downwards.

Thanks

Brian
Hello Brian, thanks so much for the information. I'll keep that in mind for sure. Can you tell me exactly what means "drive with the throttle closed". Don't want to misinterpret what you're saying.
 

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2012 Rio5 EX 6spd
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Hello Brian, thanks so much for the information. I'll keep that in mind for sure. Can you tell me exactly what means "drive with the throttle closed". Don't want to misinterpret what you're saying.
Foot completely off the gas pedal - if your foot is even lightly on the throttle the injectors are firing. I know it sounds a bit odd, but it's quite possible. Many people will stay on the throttle until they transition to the brake, which isn't the most efficient.

Hope that helps,

Brian
 

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Hello
I want to change my tires from 175/70/R13 to 185/60/R14 or 175/65/R14
wanna know how much my fuel consumption will goes up by using 185 instead of 175/65/R14?
my engine is 1.5l
 

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farshidkh I think you are on the wrong forum.3G Rios come with 15 inch wheels or 16 or 17 .
 

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2014 Sorento EX V6 AWD, RIP 2003 Sorento EX 3.5L
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When it come to tires/wheels and fuel economy, light and narrow will do better, because there is less rolling resistance. There is less mass , which makes them easier to spin, and narrow means a small contact patch, which is less drag.

Agree 100% from my own experience. Purchased a set four new slightly wider and much better tread all-season tires and noticed the SUV did not roll as long as it used too and the gas mileage went down. As soon as these tires get old I will replace them with standard size medium quality and hopefully my gas mileage will get better again.
 
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