Tire rub on 2010 550i w/M Sport package

[h2oskiphil]

Bought a 2010 550i with the M Sport package used about 2 1/2 years ago with around 80k miles. I've put 30k on it since then-absolutely love driving this beast. The previous owner put larger wheels and lower profile tires on the car (275/30ZR19's on the rear, 245/35R19's on the front, Style 95 offset wheels 9x19 front, 10x19 rear). Over time, I've started getting a tire rub on the fender lip on the rear tires when I hit bumps, and it's getting progressively worse. Originally it only happened when I had 4 people in the car and a full tank of gas and hit a big bump that caused a lot of rear suspension deflection....now it happens with just me in the car and the severity of the bumps that cause the rub is getting smaller-mild bumps cause it now. I've replaced the rear struts with the OEM Bilstein units, and that didn't fix anything. It's getting so bad that the fender lip on the driver's side is actually wearing a groove in the sidewall of that tire (there's a section of that fender lip that looks like it caught the tire and got dimpled out slightly, which caused even more wear to the point where there was rubber stuck to it). I bent that back, but it's still hitting and I'm not comfortable driving it for fear that it's going to destroy that tire.

Would spring wear over time cause this problem? Should I replace the springs with the OEM spring that came with the car originally (I THINK my dealer figured it out-realoem.com doesn't show a part number for the spring, and I understand that the spring part number is VIN specific)? Should I go aftermarket coilovers to raise the ride height slightly (or stiffen up the shocks) to make some room for those bigger tires and wheels to move around the way they need to? If so, any recommendations on coilovers?

I love the way the car drives right now....it's like a go cart in corners, but I have to do something about the tire rub before it destroys a tire going down the highway. Appreciate any advice or feedback.

[ABCarr]

The tire sizes you are running are the stock M Sport sizes. The Style 95's you have are wider and have different offsets than the stock Style 172's that are normally on M Sport 550i's. Style 172 are 19x8.5 ET18 (front) and 19x9.5 ET32 (rear). I am a bit surprised that you have outside rubbing on the rear tires with your ET24 rear wheels. On my 2009 550i M Sport, I have the standard 172's and stock tire sizes with 15mm spacers on the rear (giving an effective rear offset of ET17) and no rubbing. That said, some tires are wider than others in the same size, and your springs may be a bit saggy now.

If I had the money, I would install Bilstein PSS10 coilovers on my 550i. You need to be careful with coilovers since many will interfere more with your wheels, which is a bit counterintuitive.

[h2oskiphil]

So if I run into an interference problem with coilovers and these wheels, would I want to put a spacer in to move the wheel away from the suspension, even though that will create more opportunity for wheel arch interference if I don't stiffen up the suspension? I'm looking at the ECS Tuning coilover kit for the non M E60...

https://www.ecstuning.com/b-ecs-part...salesrep=jared

[ABCarr]

Originally Posted by h2oskiphil

So if I run into an interference problem with coilovers and these wheels, would I want to put a spacer in to move the wheel away from the suspension, even though that will create more opportunity for wheel arch interference if I don't stiffen up the suspension? I'm looking at the ECS Tuning coilover kit for the non M E60...

https://www.ecstuning.com/b-ecs-part...salesrep=jared

Spacers would be the only option to get away from inside interference with coilovers. With your rubbing worsening over time, it's a fair guess that weakening springs are the culprit. With the coilovers, you will be on fresh (un-saggy) springs, and will have the ability to fine-tune the ride height and overall stiffness via damping adjustments, so you should be fine.