I bought a 328i Sport in Dec 2013 with 18,000 miles. At the time it had Conti SSR Run Flats with 50-60% tread life remaining (225/45r18 Front & Rear).
This was my first BMW and my first experience with Run Flats so I wasn't sure if the road noise was normal. In the past I had used Tire Kingdom for balance/rotation/alignment. I learned from the first few months of ownership that that was not a suitable option for my BMW. They had screwed it up a couple of times and I had a new alignment/tire balance performed by the dealer which Tire Kingdom refunded me for.
After much research I decided to bail on the run-flats and live on the edge. I selected the Pirelli Cinturato P7's. They have excellent reviews. (
http://www.tirerack.com/tires/tires....ll+Season+Plus)
My local Discount Tire Store was able to match Tire Rack's pricing so I got them there. They installed them and I was off. Compared to my worn out run-flats they were much quieter and smoother.
After about a week I had my first highway drive and noticed at higher speeds (45+) that the steering wheel had a pronounced wobble/vibration, not too serious but it was noticeable/irritating.
12/2: I went back to Discount Tire for re-balancing. They said that a weight had fallen off, and I was on my way again. The tires were smoother, but again once I hit the highway the vibration/wobble was back, although less noticeable.
12/4: I got a call from Discount Tire about my recent visit and subsequent survey response indicating that the tires were still not perfect and I would be taking it to BMW for re-balancing. The manager offered to refund me the cost of the balancing and/or swap out my Pirelli's for another tire, he mentioned Michelin. I am very impressed with his level of concern.
12/5: BMW dealership performed a tire balance. They said it was 'out' I drove off, and it was very smooth, yet there is still a noticeable wobble/vibration in the steering wheel from about 45 -70mph.
Now I don't know if it's the car, the tires or what!
Any suggestions? Thanks for reading all this, it's longer than I would have liked.