Originally Posted by bnj
Bmw uses Rft's for a reason. I have e92 335 that has perfect handling. Magazines seem to agree. Bmw mates the suspension to RFTs. You compromize the handling by altering tirewall stifness. Have another car if you want just a comfortable ride.
The runflats are heavy and crash over bumps, and don't stay planted as well as a "real" performance tire. Leave your suspension alone and replace those crappy tires with PS2's and then try to tell me your car doesn't ride AND handle better with the new tires. Not only are both improved, but the difference is dramatic. Ask ANYONE who has done this and you'll get the same answer.