Avon Mud Terrain 33-12.50/70R17
 

Math would have told me that these tires should affect my odometer. The specs say 33in in diameter compared to the 31.4 of the factory Michelin 265R70-17. The specs on that tire say 657 revolutions per mile.

When I checked on the Mud Terrains, the spec said 640, which is a lot more than I expected it to be.


33x3.14 = 103.6/12 = 8.64

5280/8.64 = 611.

However, a precise timed run at 60mph indicated over three miles came up to 2:58. Two seconds off.

Either the originals were reading low...or what?