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12-17-2009, 02:22 PM | #1 |
Drives: Toyota Yaris and Corolla Join Date: Dec 2009
Location: Toronto
Posts: 5
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Yaris Tire size and Fuel Economy
Hi
I am wondering as if using P175/65/R14 would result in better fuel economy that P185/60/R15 tires on Yaris Sedans ? 10mm of lesser tire width should result in lesser friction between tires and road thus lesser (better) fuel burn. Any experiences ? Regards 77W |
12-17-2009, 03:16 PM | #2 |
What?
Drives: 2007 Yaris LB Join Date: Nov 2008
Location: Safety Harbor, FL
Posts: 1,006
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Makes a difference, but I'm presently running 215's and still easily getting 38-40 mpg average around town. More important is that they are properly inflated.
If you do a lot of highway driving, running a slightly larger diameter tire (like a 175/70-14) will effectively raise the final drive ratio, reduce engine rpm and save some fuel. |
12-17-2009, 03:54 PM | #3 |
Drives: S sedan Join Date: May 2009
Location: MI
Posts: 120
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Punch in the tire sizes at: http://www.miata.net/garage/tirecalc.html
You'll notice the 14" tire spinning faster than the 15" tire at the same speed. This will result in the rpm being slightly higher at highway speed. So, any gain you might have in 10mm narrower tire will be wiped off. |
12-17-2009, 04:22 PM | #4 |
Audio Junky
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they are right... for city 14 would be best... for hwy driving 15" would probably be best. I've often thought about upgrading from 15 to 16" since I do about 70% hwy.
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12-17-2009, 04:23 PM | #5 |
Drives: 2007 Yaris HB 5-spd Join Date: Dec 2009
Location: Duluth, Minnesota
Posts: 29
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That tire size calculator just went to my favorites. Very helpfull.
So what is the stock tire size on Yaris HB's? I currently have 195/60/15's but believe they are larger than stock. Brenton
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I can see for Miles and Miles... |
12-17-2009, 05:33 PM | #6 |
What?
Drives: 2007 Yaris LB Join Date: Nov 2008
Location: Safety Harbor, FL
Posts: 1,006
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Don't get too wrapped up in wheel size, guys. It's the diameter of the TIRE that is important here.
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12-17-2009, 05:36 PM | #7 |
Drives: 08 Yaris Sedan Join Date: Oct 2008
Location: California - Bay Area
Posts: 2,773
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I do know when i jumped to 205s my milage went down 1-2mpg so going down a size i would suspect you may gain 1mpg
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12-17-2009, 05:43 PM | #8 |
Only Happy When it Rains
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Also weight. Weight can vary quite a bit even in tires that are the same size. Unsprung weight effects everything more, and supposedly rotational mass of the tires effects it even more. I read somewhere that 1 lb on the tire is like 4 lbs above the suspension. Not sure if it is true or not.
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Colin Chapman disciple |
12-17-2009, 05:59 PM | #9 | |
Drives: 08 liftback 5spd Join Date: Oct 2008
Location: adirondacks, ny
Posts: 220
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Quote:
larger tires will also display less fuel economy than is being achieved as the vehicle will travel further than will be displayed (unless using scangauge type tool to compensate). |
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