Tair

I decided to post in LT1 Tech instead of Wheels and Tires cause this is not exactly a wheel brand or tire brand specific question. Anyway, I'm gonna go from a 26.1" tall tire to a 24.5" tall tire. How much will this affect my gear ratio?

Tair

Alright, I found my answer on an fbody gears calculator website. Just so you guys know, switching to a 1.5" shorter tire means I will shift from 2nd to 3rd at 94mph instead of 100mph. (I have an A4 2.73 gears)

OldSStroker

As you discovered, it's just the ratio of the tire diameters:

24.5/26.1 = .9387 or 100 x .9387 = 93.87 or 94 mph

26.1/24.5 = 1.065 or 2.73 x 1.065 = 2.91, so it acts like you changed axle ratios to 2.91.

Tair

yay.....2.91 gears for me instead of 2.73's!!!! hehe jk

Brent94Z

That also means your speedo will be off by that much too... unless you get the PCM "fixed"

Tair

yea....guess I'm gonna have to get madwolf to gimme a new internet tune