I purchased my 2011 BMW 335I X Drive mainly becausse it was a std. trns. (Six Speed); it also came with the M package which meant Run Flat Tire w. 225/40R18 in front and 255/35R18 rear. The Run Flats were Summer Only and in Rochester, NY we have Winter Only so I replaced the Fun Flats with the same size Non Run Flat Michelin Pilot Sport and the dealer gave me credit for the exchange. The front tires show hardly any wer after 30 k miles and the rear were replaced and after 12 k miles and they again need replacing. I’m over 70 so I don’t burn rubber and would appreciate your analysis about the difference in front-to-rear wear.