The guy I ordered them from said they new tires would be wider, not taller. I haven't got them on yet, still waiting to get them in. Will I loose any performance?

Old tires:
255/70/16
Cooper Discoverer HTs

New tires:
265/70/16
Firestone Destination LEs

Are these Firestone tires any good? They were only $79 each. Oh well, if they hurt my performance, I'll make up for it when I get my Eaton/4.10s in January!

 

255/70 16 = 30.1 x 10
265/70 16 = 30.6 x 10.4
The new tires are about 1/2" taller. Shouldn't make much of a difference performance wise.

 

they guy you ordered them from is a moron. the middle number in a tire size is a percentage. it means the sidewall will be approximately 70% of the tread width. 70% of 265 is more than 70% of 255 so the tires will be taller

they're a little taller, so they will give you a little less gear. you'll prolly feel the difference now with the 3.42s but once you get the 4.10s it'll be nothing

 

265/70/16 is optional size on GM Trucks and SUVs and 245/75/16 is standard (at least on many). Both are the same height. 255/70/16s would actually be shorter than stock. Hmmmm.

 

actually on the 1500 trucks i believe 235/75/16 (the tire size i had) came stock and 255/70/16 were optional

i think the tire sizes you mentioned were for avalanches and SUVs

 

You all must run 2wd trucks. My Z71 came stock with 265/75/16's on it. I put a set of Toyo S/T 275/60/16's on it. Going from a 31" tire to a 29" tire really helped my low end. Recently I went to the opposite extreme and put a set of 285/75/16's on it. with a 32.75" tall tire and 3.73 gears I lost quite a bit of low end. With the taller tire the truck will shift into second at 80mph. Makes for a wicked good time when I am passing on the highway.

 

I did the same as above. Except I got the wrong tires and ended up with like 8 or 10 ply tires and they are very heavy. But it looks a hell of alot better than the 265/75/16s that came on the truck.