Just wonder if i should get 215/40/18 instead for '09 lowered MCSa. It seems this size is most commonly used.

 

205/40-18 is oem size, but I like 215/40-18 is a better size IMO.

 

Tirerack.com lists the Ultraleggera as 18x7" +42mm offset and you are lowered (how much?)

Standard tire size for that rim and for the MINI is 215/35-18

First 205/35-18 doesn't match any tire at tirerack.com so it is not an option.

215/35-18 fits rims 7-8.5" wide and has tire diameter of 23.9" which is slightly less than stock which is good for a lowered MINI.

The tire selection for this size is very good- including very good handling Max and Ultra HP summer tires and some good All Season tires with a range of usable prices.
see
http://www.tirerack.com/tires/TireSe...er=18&x=20&y=8

The downside is a 35 series sidewall is a little stiffer for daily street driving especially on poor roads.

215/40-18 is too tall for a lowered MINI at 24.8"

see
http://www.tirerack.com/tires/TireSe...er=18&x=20&y=8

Tire selection is not quite as good as 215/35-18 but comfort for daily use would be a little better depending on which tire you select. Anything built with a stiffer sidewall which is better for crisp handling would be potentially stiffer riding and sometimes a little noisier.

205/40-18 is the runflat size for the MINI and only a few other tires like Yokohama S.Drive come in that size. It will fit the wheel and tire diameter is a stock sized 24.4" so that would be OK.

 

205/35/18 is a toyo t1r size

 

Possible. I don't see many other options in that size.
see
http://toyotires.com/tire/pattern/proxes-t1r

205/35ZR18 81Y load rated 7.0-8.0 rim 23.7" 8.3
215/35ZR18 84W load rated 7.0-8.5 rim 23.9" 8.6

81 load rating is a bit low for a MINI used for daily driving
Normally look for about 84 to 87 load ratings.

If you are driving alone and don't usually put anything in the car then 205/35-18 could work with that wheel size and be the right tire diameter for a lowered MINI.

Realize too that a 205/35-18 will have a shorter sidewall than 215/35 by a little. More aggressive looking but firmer ride.

In 205/40-18
Nitto Neo Gen 24.5" tire diameter, ultra HP all season tire
http://www.nittotire.com/#index%2Etire%2Eneogen

I don't see any Falkens for that size.

 

Thanks for all the inputs guys. I called the shop and changed to 215/40/18 Nitto NeoGen. Need to wait for them to ship.