tire sizes

i got a '99 tahoe not too long ago and was wondering what the maximum tire size i can go with. does anyone have an idea? i'm probably getting 15" rims and want to fill out as much as possible without doing a lift kit.
thanks.......

It depends on whether you have 4wd or not. I dont know about 15" rims, but i have 16" rims and 4wd and I fit 285/75's which is about 33"x11.5". But I also have a 2door, but i'm not sure if that makes a difference. Go to the tire place you plan on buying them from, they will better answer your question.