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Old 09-10-2013, 09:58 PM   #104 (permalink)
rmay635703
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Join Date: Jun 2008
Location: Somewhere in WI
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Silver - '10 Chevy Cobalt XFE
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Quote:
Originally Posted by TexasCotton View Post
IMHO
I am going to try the 175/65R-15 and take off OEM 185/65R-15.
I value all opinions. However first hand knowledge is always a better indicator than others basis/speculation/ and opinion
On my cobalt I went from 195/65's to 185/65s, my revs per mile are almost negligible (apparently the cheap 195's rolled almost as much a s the 185) (aka well under 5%) odometer is off under 2 miles per every hundred run

My fuel economy went up relatively dramatically but weather and heat have more to do with it.

Also the goodyear "energy saver" tires included with the car stock really weren't energy savers at all might also affect it.

I have a feeling if you could find narrow tires that were taller AND energy savers (good luck) you would probably gain FE.

AKA stock 195/60's to 185/65's for example, in my case the cheapness of the brand/type of tire made the difference end up being less than expected in terms of ODO error.

Now if one could find energy saver 165/80s then you gain aero while maintaining most of the load capacity and the same odo/gearing

But alas nobody makes 80 or 85 form factors anymore for decent new tires. just one off antiques.

Something I often wondered was if one where to downsize rims, but have taller tires what affect that might have since the load capacity would go up AKA 195/60r15s to 195/85r14 for example.

Ah well.
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