E46Fanatics - View Single Post - Autocross Tires for 2013
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Old 04-25-2013, 02:20 PM   #3
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Join Date: Apr 2008
Location: Boston
Posts: 4,971
My Ride: 2003 325xi
Originally Posted by murph1379 View Post
I think you'll find that the acceleration differences are much more in the gearing (tire height) than the weight. Even in a torqueless car like a miata, it's hard to notice weight differences in lap times. (GRM actually tested this)

I'd recommend a 245/17 or 255/17 on a 9"+ wheel.
I have a 8" wide 17" wheel or a 8.5" wide 18" wheel.

A 235/35/18 would be nice but not available. I am leaning toward a 235/40/17.

Interesting question- what's faster on a torque-limited car: 235/40/17 at 24.4" tall or 245/40/17 at 24.7" tall.

Keep in mind I will have to lose some front camber if I go up to a 245 in order to stay in my class. We have 5 BMW autox classes in the Boston BMWCCA and a finely tuned points system to determine which class you run in. If interested, check it out here: http://www.boston-bmwcca.org/Autocro...ification.aspx
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