What is the largest tire size I can put on a 2002 Silverado 4x4 1500 without putting a lift on it? I have a "Superchips Cortex" programmer so I can make adjustments for tire sizes if that is an issue. Is it an issue with larger tires than the factory P265/75R16? I am interested in upgrading my rims to a larger size such as 18, but do not want to go with 20 or 22. Please pardon this noobie question. I'm a bit confused by all this. I know larger tires won't dramatically improve any performance issues, just thought they would look really nice.