Tires: tire sizes, size tires, ford f250

Question
I have a ford f250 with 275/70r 18  factory size tires can i replace them with 275/65r 18  will this affect accuracy of the speed on my odometer   thanks Bob

Answer
Bob,

No, you can't replace them with that size.  Not only is the tire smaller in diameter which will throw off the speedometer and odometer, but you are going down in load carrying capacity which increases the risk of a failure - and sometimes those result in crashes.