gpinkwater

How big can you go on a stock 550i without rolling your fenders being sure there will be no rubbing? Are you sacrificing signifcant stopping/handeling characteristics going beyond a 19" wheel?

EuroCarFan

The answer is not so simple. There was a member here with a 530 that had 22s and lowered without rubbing. But there are other people who have had 20's and encountered rubbing. It depends on the offsets of your wheels and even the brand of tires used since some have rounded and some have squared shoulders that can contribute to rubbing.

Anytime you go to a bigger wheel/tire combination, you'll sacrifice performance, handling and ride comfort a bit so if you're concerned with that, then stick with 19s. That said, if you choose a bigger wheel that's lighter than 19s then your performance should actually improve. Note though that even if the rims are lighter, bigger tires can neutralize any weight savings.

Another thing to consider is aesthetics. I think most people agree that 20s look perfect on this car. If you go with 19s, get wheels with no lips so it'll look a bit bigger. 19" wheels with lips tend to look small on the E60.

TAJARO

For the sport package suspension- I think the safe operating box that has been found is 25.75 inch (655mm) with net offset (including spacers) of 10-15mm up front , and same diameter and offset without staggering. If you do stagger then net offset of about 25-30 works with 40mm extra width on the rear. Max front width is 245mm and you can stagger up to 285 on the back. Members working within this box report no problems.

So work your rim/tire size from there. 245/40-18 and 285/35-18, 245/35-19 and 285/30-19 fit. 245/30-20 and 285/25-20 should work. I guess 245/25-21 and 285/20-21 calculate also if you could find (and afford) the tires. Of course the life expectancy of those sidewalls make them impractical for me in rural PA and I can't justify buying a new tire and risking a busted rim every few months.

Personally I think the 19s are perfect for me but send pics whatever you do.

acuteperformance

On my 545i w/ coilovers I had 20x9/11 255/35/20 295/30/20 no rubbing issues. I couldve actually gone 305/30/20 in the rear no problems. However, what are you looking to do? I generally tell my clients 20x8.5/10 245/35/20 275/30/20 to ensure fitment w/o rolling fenders.

Michael
Acute Performance

EuroCarFan

I should also add that on my old 545, when I first put on 20x9/10s with 245/35/20 and 275/30/20 tires with the factory sports package, it rubbed. But then I switched to KW V2 coilovers and was able to lower the car more yet the rubbing was gone. That was because I was able to adjust the shocks with the KWs to make them stiffer so the chassis didn't move up and down so much. So what kind of suspension you run is a huge factor as well which I forgot to mention above.