Tire size = Speed

N

newjeepowner

NAXJA Forum User

Location

Roseville, MI

• Jul 30, 2007

• #1

I am putting 31 X 10.5 X 15 tires on my 99 XJ. The stock size was 235 X 71 X15. What kid of MPH difference will I experience? How do I go about fixing the difference?

 

goodburbon

NAXJA Forum User

Location

Westcliffe Colorado.

• Jul 30, 2007

• #2

well you are waaaay off on your stock tire size

 

goodburbon

NAXJA Forum User

Location

Westcliffe Colorado.

• Jul 30, 2007

• #3

a true 31" tire will put you almost 10% off from stock.

 

lancey3

NAXJA Forum User

Location

Columbus Ohio

• Jul 30, 2007

• #4

change the speedo gear in the tcase fixes it.

and stock i think is 205 or 215 not 235

 

N

newjeepowner

NAXJA Forum User

Location

Roseville, MI

• Jul 30, 2007

• #5

235 is whats on there now. I bought the Jeep like this. I thought they were the stock size. Where do I buy a speedo gear? Part #?

 

goodburbon

NAXJA Forum User

Location

Westcliffe Colorado.

• Jul 30, 2007

• #6

at the stealership. you need to know how many teeth are on the one you have now. Takes 5 minutes to find out. multiply that number by 1.1 and it will put you back right.

235 isn't a stock size, and by "off" I also meant that it is 235/75/r15. not 235 71 15

 

N

newjeepowner

NAXJA Forum User

Location

Roseville, MI

• Jul 30, 2007

• #7

opps. I did not realize I type in 71

Thanks for the info.