Does size really matter ...?

I'm in the market for some new tires. I'm currently running 265/70/16s and wish to maintain my stock appearance for the most part. The BFG Rugged-Trail T/As need replacing big time. When I bought the truck back in February, I knew that I would need new rubber sometime in late summer, early fall. I went checking around at the local BJs wearhouse and found some Michelins that might do the trick. I found a set of 265/75/16s which I think would look great on my '07 DC Off-Road. They aren't cheap but they come with all the bells & whistles. The other set of Michelins are the same size tire I'm running presently.

My question: What advantages / disadvantages would I be experiencing should I go with the taller tire (75s) versus the shorter tire (70s)? I'm not an expert on these things but aside from the beefier look, would I be setting myself up for worse gas mileage (I'm presently getting 19 - 19.5 mpg with my 6 cyl.) or any other issues I might encounter down the road? The taller size costs roughly 30 bucks more a tire.

Any thoughts? Thanks.

 

I think you should be fine with that larger size. You won't even tell the gas mileage difference between the two because the 265/75-16's are just one size larger. You should be good to go.