Rear tyre clearance to bumper

[elmof1]

My rear tyres only have a couple of mm clearance to the rear bumper. I'm running 195 50 15, so fitting 45's would help, has anybody just spaced the bumper back a few mm before?

[Jonny5]

45s would clear better due to the smaller rolling radius. They would also be closer to the standard wheel diameter which would mean the speedo would be more accurate.
The flip side is people say they handle and ride better on 50s.
Spacing the bumper out is also quite a common thing to do so whatever is easier for you mate.