350i ride height

[billvet]

can anyone help with a ride height query - I recently bought a 350i which came with a "selection" of rubber on all four corners which proved to be a very entertaining drive from Cheshire to Nottingham in pouring rain.I have replaced all four tyres which were a collection of 205/60/15 cheapos with Continental 225/60/15. The problem is now that the rear body is rubbing on the tyres. The main question is have I overtyred the car or do I need to fit uprated springs to increase the ride height at the rear or do I need lower profile tyres? Any thoughts appreciated.
many thanks in anticipation
Bill

[billvet]

many thanks for the replies - yes both sides rub and I can physically lift the body to clear the tyres but when I let go it drops to within 1/2" of top of tyre and definitely rubs when moving. The previous tyres did not rub but were rubbish. The wheels are original BHS 7x15 as shown in the Wedge bible. Any idea where I can get uprated springs? I'll also look into increasing body packing.
Again, many thanks for your replies
Bill

[billvet]

Just measured relative heights from ground to top of wheelarch
FL 65cm FR 64cm
RL 64cm RR 63cm

[billvet]

Once again thanks for all the comments - I think I'll change back to 205/60/15. The Contis can go on the BMW.