Does anyone have a link for a tire size conversion chart. I want to figure my true mileage but cant find anything that will do all the math to let me know how to figure it out.

Thanks

 

go to 1010tires.com they have a tire size calculator it works great

 

That site is awesome.

Thanks.

 

Thanks dgm1958

 

The chart says my speedometer is 8.398% too slow. How can I use this to find out my true mileage? Thanks for all the help!

 

If you are just trying to figure out your real mileage just multiply the mileage on your trip meter by 1.0839. This will give you the actual mileage traveled.

For your speed I would estimate up to 10% difference then take 10% of your speed and add it to what is showing.Why 10% b/c it's easier to calculate in your head.

TripMeter/Odometer
546.8 x 1.0839 = 592.6

Speedometer
65mph x 10% = 6.5 so you would be right below 71 MPH
Actual would be 65mph x 1.0839 = 70.45mph

 

Thanks for the help everyone.

 

This is what you're looking for...hope it helps.

http://www.miata.net/garage/tirecalc.html