Originally Posted by derekh929
Pete bang on the money i have moaned to BMW at big events for as loan as i remember about run flats, always the promise they will stick by them as will improve but there was no way to do this on very low profile tyres unless they reduced the ridged ness of the side walls giving less miles on in emergeny and thats what they have done. You just need to drive a couple of Alpina car's to relise the damage to ride they do.
I remember a motor show when i was speaking to one of the suspension guys from BMW in 2007 i was invited up with a few others to have a chat on what we felt the issue was with e90 m sport and they must have been worried all present sales unless ride improves or got ajustable suspension they would lose market share to other brands, as my street was an example one moved from old 5 series to e class another to Audi and a few more, two of them back to 5 series with adaptive damping, or non RFT.
I think the Adaptive was put on spec list due to the facts above to keep the hard core BMW car buyes that buy not for the badge or looks , but that does help, but for the Drive train and 50/50 balance and also well controlled and compliant handling. Not all owners are looking for this
I'm aware others were pushing hard on BMW, we had my dealer co-ordinating with BMW Technical, to sort 3 cars with very disgruntled long term customers. We thought BMW were going to use one car and test different wheels, then BMW backed away. I personally think they realised they were getting too close to finding a wheel/suspension mis-match issue and didn't want any of us to confirm it.
Without going too far off topic, I went straight to BMW Technical and Bridgestone, (as I said BMW backed away), but I managed to get a Senior Bridgestone Field Engineer up here for a morning, and we went out in my car for him to see for himself what we were dealing with, when road quality was not of typical 'test' standard.
It was clear I was pushing the working envelope up here and the suspension was not coping with the RFTs. Obviously he had much more to say and went off to investigate the issues further. Hence why I went for Koni FSD dampers to widen that restricted envelope. Was still not enough for the driving quality I was after. Now we have active damping systems which widen that envelope even more, when conditions start pushing the boundaries.