I have a 2010 SLK 350 with the Sports Pkg. Frankly, I'm not thrilled with the suspension, because the ride is similar to a hay wagon!
I'm thinking about going back to the standard or non-sport pkg setup. Looking at a MB online parts website it doesn't look too difficult to do:
The front struts & springs along with the rear shocks & springs need to be replaced. I was considering using all MB OEM parts except for the front struts, R&R them for Bilsteins. So B6 or B8?
I have a long email conversation with Bilstein Tech Support who told me the B6 is the correct replacement. I questioned this, because in previous inquires, I was told B8. To resolve my confusion, I was able to nail down the difference between the B6 & B8 from the horse's mouth.
I would happily post the entire conversation here except it's privileged. Hence, I'll give you the essence of it:
"According to our interchange the B6 is the direct replacement for your vehicle. In further investigation our B6 and B8 products for you Mercedes have the same valving profile/ride characteristic just the B8 has a slightly shorter travel stroke. The housings of the shocks are dimensionally the same between the two. Only difference is the travel. For your vehicle the B8 would be a more appropriate shock if you were using an aftermarket lowering spring."
That makes sense, since a lowering spring would be shorter and stiffer and wouldn't need as long a stroke as the normal/standard spring.
Finally, I'd like a favor from a member who might have a late model R171 350 without the Sports Pkg. A 2010 would be nice, but something earlier might do. I want to find the MB part#s for the front and rear springs. On the front spring, there is a color code painted on the spring. The same for the rear spring, but it might be difficult to see.
BTW, for those of you who might want to lower your cars, I'll have the complete Sports Pkg suspension components available.