So my jeep x came stock with 225 just installed 295/75r16 how much would my odometer be off i know my speedometer is off 10 mph i think according to discount tire.

 

1.3445634 1/2 miles, or 2,345 feet, orrrrrrrrrrrrr 4,455,443 inches. Seriously though, I'm not sure....nor do I think there is a way to find that out. if there is, I'm sure someone will chime in and help you out.

 

There is a way to know, but we need your complete OEM tire size. You just provided the width.

 

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

Based on a 225/75/16 oem size, @ 60mph on your speedo, you're really doing 68.5

 

OEM x or current sport c package tires are 225/75 r16

 

((New Tire Circumference/Old Tire Circumference) x Total Miles Driven On New Tires Per Odometer Reading) + Odometer Reading At New Tire Addition = Actual Mileage

It doesn't matter if you measure your tires in inches, mm, whatever, as long as your old and new tires are measured using the same units. Both in mm, or both in inches... you just need that proportion for the equation.

MPH measurement difference is not steady. It would be a curve if graphed. The faster you go, the more your speedo is off.

Hehe... I had the formula wrong at first and had to change it. Hopefully I got it this time!