i need help asap!!! i bought prostars 15x8" with 5.5 backspacing and everyone said that i wont need spacers. I jus put them on and they rub. Plus before i had draglites so my calipers r grinded way the hell down. I need to kno what to do? Do i need spacers? If so what size?

 

Where do they "rub"? On the calipers? If so, you might just need to grind the calipers down a bit more. I run 15x10" Pro-Stars with 7.5" backspace, and after grinding the fins down, they fit fine. Photo link to a picture of the ground down caliper in the FAQ "stickied" at the top of the Wheels and Tires forum listing page.