I am thinking of getting 18" rims for my R56 but don't really know the advantages of them beside looking kind of cool. What's your opinion?
Thanks.

 

Looks are about it. They add weight so most people tend to stick with 17's or some "ultra light" aftermarket 18's

 

For me the disadvantages outweigh the advantages. The 18's will give you more road feel. But if you hit a pothole, driving at night for example, you have a greater chance of damaging the rim.

As far as handling, on this forum the opinions differ about if a smaller or a bigger wheel gives you better handling.

 

Less sidewall to flex so better feel and handling. But be prepared for a harsher ride. Tires are more expensive, too.

IMO, they do look nicer on the R56, but not sure its worth the tradeoff.

I'm dying to see a slammed MINI with 20" wheels. Now that would be a "go-kart" ride.

 

A lot of the autox and racers are going for 15" and 16" wheels to reduce unsprung weight. The sentiment seems to be that the advantages of a short sidewall are overcome by the disadvantages of heavier wheels. It seems that the 18" folks are doing it for looks.

 

small side wall means less slip angle available, which means less feed back at the limiti.

i would go with a wider 17 vs a 18 anday. 235.40.17 on a 17 x 8

 

Which 18" rim? Aftermarket or stock?

18" rims-
Allow for greater clearance for any big brake kit- not really needed for stock R56 brakes or JCW brakes. Oversized or larger calipers will need more clearance so large rims allow for that.

Allow for shorter sidewalls like 30 or 35 series tires but that also means rougher riding most of the time. Stiffer sidewall also means more risk for damage to the wheel, tire or suspension if you hit a pothole going fast. And less comfort for daily street use. If you don't have very smooth roads then shorter sidewalls get old quickly.

Allow for the big wheel look- combined with lower profile tires. Very sporty but not very practical. Also very heavy unless you buy aftermarket and pay a lot more, then you can find some lighter rims but it will still be fairly heavy compared to 16" and 17" rims. Heavy tires and rims are not very useful for the Base Cooper but an MCS has enough power to deal with it.

Allow for good handling given the lower profile tires but so do good 17" rims and 215/40-17 tires without the extra weight.

Allow for some rims that only come in 18" size.

Allow for a unique and non stock look. Possibly closing the wheel gap without adding lowering springs if the 18" tire is slightly taller than stock 24.3" which many are (about 25"). Just don't go too tall.

 

No real advantage except looks, if you're into that type of look. IMO 18" wheels are too big on a MINI. 17" wheels are the perfect combination between looks and performance.

 

The bigger tires are more expensive, harder to mount, and eliminate some of that pesky fuel economy that nobody likes.

 

The advantage of 18" is that now I can tell the quality of the freeways and which one needs repair! Seriously, the ride is quite harsh even when I am using a higher side wall than normal (225/40/18). All my other cars before the Mini are sedan, SUV, or van with 65+ side walls. I still like my wheels, they look really nice... but that's about it.