I've got a slight chafing issue on the rear of my S40.

Running 225/45 R 17 both front and back.

A drop to 215/45 R17 should should the issue as it's just fouling the arch by a couple of millimeters on big bumps.

My question is.... will a car pass it's MOT etc... if the front and back tyres are a slightly different profile?

Cheers - Ben