I just got new tires, I went from 255/65/17 to 265/70/17, about 2in difference in height. Revolutions per mile went from 685 to 651, i'm guessing about 5% slower?? ( I smoked too much pot in school..lol..)

 

Your tire diameter went from 30.05" to 31.60". Thats close to 5% difference in diameter so your speed odometer will read about 3 mph less than you are actually going.

 

that shouldn't make any problems will it?

 

As long as you remember when cruising along that you are going a little faster than the speedo reads, no, it will not cause any problems. Your actual mileage will be off just a little over time also, but it will be to your advantage, the truck will have a few more actual miles than the odometer reads.

 

Your speed and odometer will be off a little, no big deal.

 

I would stay below the speed limit about 2 or 3 mph.

 

mom's a sheriff, got 8 courtesy cards. don't speed to much anymore that's why I have 8..lol

 

http://www.1010tires.com/TireSizeCalculator.asp