Wheel size Help

[AZcoyote52]

I currently have a 2008 2500 HD LT duramax with 16" wheels on it. I am wanting to put 17" wheels instead. The wheel wells are so big on this truck that the 16" wheels and tires look small in them. My question is this: What impacts will I have if I make this change? One other thing: What is the biggest size tire in the 16" wheel that can be put on the truck? Thanks

 

[Off Road King]

a 17 wont change you mpg much, but I would stay with the 16, get a set of 285s, If you ask me, it comes out perfect, and you mpg will barely change, maybe 1 less... even if you get 10 ply tires