Sorry for the noob question, but I came over from jeepforum.com. I know Jeeps, nothing about full size. My roommate just bought a 2009 Sierra SLE crew cab 4x4, 5.3L if that matters, pretty much the base model. The stock tire size is 265-70R17. She wants beefier tires, but I have no idea what size to put on there for her. I know she doesn't want to do any suspension mods (lift or lower), and wants to keep the stock wheels (don't know if that matters either, but they're the stock alloys with 6 spokes). By eyeballing it, it looked like my tires would be a good fit (33x12.5R15) but I wasn't sure how they'd clear in the front. I'm running BFG MT's that I really like, but I don't know what she'd want. Any recommendations on a good size? It's going to stay on the pavement, except for some light-duty camping. Just looking for a nice beefy look on stock wheels. Thanks.

Also, what other factors are there on Sierras? Don't think gearing would be an issue with a mild size upgrade, but what about calibrating the speedo?

 

Hi I have a 08 Silverado and the stock wheels for it went from 17s to 18s.I would look on the drivers door to make sure.If they are 17s then moving up to 285-65-17 should be about all you can put on the stock suspension.It would give her a wider tire with about 1.5in of height.You could put a 2in lift on the front with a kit that is easy to install and would give the truck a even look from the back to the front.