CC89Formula

do taller tires effect gear ratio? if they do, how and by how much? thanks in advance

AlkyIROC

Installing taller tires is like going to a lower gear ratio. Like going from 3.27 gears to 3.08.

Installing a taller tire without changing the gear ratio will increase fuel mileage since it will lower the engine rpm while going the same speed. The speedo will need to be recalibrated the same as swapping gears. Taller tires will be slower off the line. Taller tires will last longer because they rotate less per mile. Taller tires will increase the top speed.

There are pros and cons to taller tires without a gear swap.

klumb15

iTrader: (1)

i would also want to know about this? i'm gonna run some taller tires too i think. I think they are 29.5..not sure tho, they are 295 width i know that...

i have 3.73's, and my speedo is all messed up, will taller tires even it out a bit

what are the pros and cons to taller tires?

AlkyIROC

Didn't I already say it?

For racing, you want the tallest tire possible then you adjust the gearing in the diff to best suit the tire size based on the engine's rpm range. For me a 30" tall tire and 4.56 gears lets me cross the 1/4 mile at around 7000 rpm.

A 30" tall tire and 2.73 gears would be terrible on the drag strip but would probably have a 160+ top speed on the highway.

klumb15

iTrader: (1)

so i have 3.73's. how tall should i go with? is there a way to figure this out other than trial and error? its a street car, that goes to the strip occasionally..

sorry about asking you the same question twice. I guess i didn't read your whole post the first time..

NHRA427

here is a gear ratio or speed calcutator to use

Ratio calc 1