this may be a retarded question, but...

[hayesvegas]

so in figuring tire sizes and how much it would throw my speedometer off, my 88 had stock 225/75/15, it has 235's now, in doing the math from the faq page, going up that one size throws my speedo off 10%??

that just doesn't seem right. its a .6in difference. when you figure it with 31's it's still under 11% for a tire almost another 2in taller. am i doing something wrong?

 

[ballinjefe22]

Tire size calculator do the math on there...comes out to about 2%.

 

[hayesvegas]

thanks. this does seem more logical.

 

[My wife said no FJ!]

Tire size calculator do the math on there...comes out to about 2%.

Nice link

 

[ballinjefe22]

it only works for the metric sizes...
Tire Size Calculator | Compare Tire Sizes ๏̯͡๏
that one is a step above and better if youre lookin for more info on it. probably saved my butt while i was still runnin stock gears with 35's :whoops:

 

[Man Jerk]

Most accurate way to do it other than GPS.

Find a streach of hwy, 10 miles long using the hwy markers.

Reset your trip odometer at mile 0, and compare what the odometer shows after you pass mile marker 10. If your odometer only shows 9.5 miles, then divide 9.5 by 10 and you get 1.05 approx. Now all you have to do is multiply your speed by 1.05 to get your actual speed.