Tires: tire speeds, chevy 2500hd, tire failure

Question
I have 245/75/R16 tires on my chevy 2500HD. If i put 265/75/R16 tires on how much will it change the speed that the truck travels

Answer
Russ,

Here is a tire calculator that will answer your question:

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

But there are 2 situations you need to be aware of.  

First is that your vehicle came with LT type tires, and P type tires do not have enough load carrying capacity for your vehicle.  So unless those tires have the letters "LT" in front of the tire size, you could get a tire failure, and sometimes those have tragic results.

The second thing you need to be aware of is that some versions of your truck came with 6½" rims and an LT265/75R16 needs to have at least a 7" rim.  Using a rim that is too narrow will tend to arch the tire across the tread face, and you may get a vehicle that tends to follow the ruts and grooves in the pavement, as well as one that is sensitive to the wind.