How is the ride with the M7 springs lowered on 18's with 215/35/18 compared to stock 15's. Is it a harsher ride or just a tad noticable. thanks in advance.

 

Compared to stock 15's ? It would be like sitting on a fluffy cloud compaird to sitting on a sharp rock ! LOL ! I run two sets of wheels. A set of 18's with 215/35/18's and a set of 16's with a 205/50/16's. It is very very hard for me to switch back to the 18's after running on the 16's. I just switched from the M7 springs to Megan Coilovers a couple of weeks ago and have been driving with the 16's and just yesterday switched back to the 18's. Even though I now have a better ride (not riding on bump stops) because I can soften the dampening, It's still a bone jarring ride on the 18's. The 18's look great but they are very harsh in comparison with the 16's.

 

Hmmm. Mine has 215/40/18's. They are ALOT smoother riding than the stock 195/55/16 runflats are. Even over harsh bumps. Car still has the stock suspension though and is a R56.

 

I don't know about an R56 on stock suspension (I have an r53) but, when comparing a 215/35/ tire on 18 inch wheels with M7 springs to a 15's inch stock 15 inch wheel and tire as asked in the post, it's night and day difference run flat or not ! believe it !