Tires: Tire sizes, chevy tahoe, fuel economy

Question
I need to buy tires for my Chevy Tahoe RWD.  I have 31X10.5R15 on the vehicle but am considering P235/75R15 the door post shows as a cost savings.  What will sacrifice by going to original equipment?

Answer
Franklin,

In my opinion, the original tire size is usually the best for overall performance.  Using something else generally improves one property at the expense of another.

In your case, you'll be going the direction of better fuel economy, better handling, better ride, better steering, and away from off road handling and capability.