[cptcolo]

Originally Posted by P1

I never liked that wheel in the first picture. So I'd go with the first option. But what kept me from getting 21s in the first place (although it's a cheap option) is the lack of tire choices. Ends up being an expensive wheel to have on the X5 due to the tires. I went through this with my F15 and vowed never again.

Yep, there are hardly any 21" tire options out there. Going with the stock OEM run-flat Pirelli P Zero Max Performance Summer Run Flats which last about 15,000miles and cost over $2,000 a set installed will cost a ton over the life of the car. Also there are no all-season options for the 21" wheels. 20" has tons of options and you get a square tire setup which allows for full rotations every 5,000miles that extend the tire life.

Personally I went with the 20" style 740M wheels and the Michelin Pilot Sport 5 Max Performance Summer Non-Run Flats. These cost $1,250 a set installed at Costco and have a 30,000mile tread life warranty (I suspect they will last about 25,000miles). These tires are less than half the cost of stock 21" OEM tires and from what I know will perform much better, as the Pilot Sport 5 is one of the best Max Performance Summer tires out there.

You could also get the 22" wheels after-market (on the 45e and 50e), but that will be quite a bit to buy a second set of wheels. Not worth it IMO. The 20" 740M look pretty dang good. The 22" tire selection is also fairly limited but still better than the 21" selection. For absolute maximum performance you could the 22" wheels with the Michelin Pilot Sport 4S, or future Michelin Pilot Sport S5 (assuming size is available) summer tires. For those that must have it I understand.

Here are a couple good review videos on the Michelin Pilot Sport 5 vs. others: