Hey everyone. I have a couple questions about tire choices for my 02 F150 4.6L Screw. It's the XLT with 16 inch rims on it, and as of now, Goodyear Wrangler RT/S 255/70/R16 tires. Now, I'm in automotive school and I know how to do the math and figure out what that is in inches, but I was looking for a knobbier tread for my next set of tires. How bad would a set of 265/75/R16's throw off my speedometer? I'm looking for a mud-type tread, or close to it, but not wanting to have to re-calibrate my speedo. It's only a 2wd by the way. All opinions are welcomed and appreciated.

 

Not much...

http://www.discounttire.com/dtcs/infoTireMath.dos

 

Roughly 3 mph at 65mph. Not enough for me to recalibrate it.

 

Google miata tire size calculator.

Has always been my favorite.

 

Sweet. That helps a lot. Thanks guys!