Tire size & M.P.H. difference

[JPhillips]

I just installed Michelin LTX 235/85/16 tires on my one ton today. It had the same tire in a 215/85/16 size. I was wondering if anyone knows for sure how much it changes the speedometer accuracy and the final gear ratio. For instance, if I am running 60 m. p. h. now, how much faster is it with the larger diameter tires. My Speedo was very accurate before. Thanks, Chris

 

[GotDodge]

215/85/16=30. 4" and 235/85/16=31. 7"

60MPH is now 62. 6MPH