What I mean here... can I theorize that 18 inch wheels with normal tires will not be any more harsh than what i'm already experiencing with the bricks (run flats) I have now? Just trying to justify the switch to 18s

 

Probably not. What psi do you inflate your bricks to?

 

I like them at 35psi

 

I only use above 33 psi when traveling at 100+ mph on the autobahn, typically weekend jaunts to Frankfurt or Belgium. Even at 33 psi the stock tires let you know they're RFs, but the extra few psi will at least soften the spinal damage around town. Mount some Koni FSDs and you'll even think your MINI on 18s is Buick-like (not really, but far better than stock). Ultimately, you have all the signs of a driver that cares as much for ride quality than outright corner sliding performance. 18s look the part of performance, but any low profile tire in that range will be stiff too. Ride quality improves with lower diameter wheels, and grip improves with less sidewall flex, very generally speaking and all else equal. Now that I have FSDs, I would consider 18s. Otherwise, I never would have. I like all my teeth to remain in the gums.

 

Yes, it is possible that 17" Runflats and 18" non runflats can be about the same in ride quality for street driving on most roads. Our sales people at the MINI dealership often remark that the JCW 18" wheels with runflats are about the same ride quality as the 17" runflats. So 18" wheels by itself can be ok.

Two options for 18" non runflat tire size.

First is 205/40-18. 40 series is not too low and 205mm width not too wide.
Selection is rather limited with runflats or only one non runflat at tirerack.com. Ask Alex@tirerack.com about the Michelin Pilot Sport PS2 for $189 each in stock. 220 treadwear AA traction 20 pounds, fits rims up to 8" wide, 24.4" tire diameter. See
http://www.tirerack.com/tires/tires....4YR8SPORTPS2XL

Second size is 215/35-18 which has a much better selection and better prices. Fits rims up to 8.5" wide. You can choose Extreme/Max Performance Summer tires or even All Season Ultra High Performance tires. 35 series is a bit stiffer sidewall but if you choose an All Season tire it should be OK and not overly stiff.
See
http://www.tirerack.com/tires/Compar...=All&x=57&y=10
Some All season Ultra HP tires to check out-
Continental ContiExtremeContact $124 each 21 pounds 400 treadwear AA traction 23.9" outer tire diameter
Pirelli PZero Nero M&S $140 each 20 pounds 400 treadwear A traction 24" outer tire diameter.
All Season tires usually give longer treadwear and reasonable traction for street use. Some give a comfortable ride as well.
See
http://www.tirerack.com/tires/survey...jsp?type=UHPAS

 

real good information Minihune, and i agree on that. I switched to 18s with 215/35/18s from RFs and it felt just a little softer, nothing big. If you do 205/40/18s, would even feel more comfortable, although they are 18s.

 

Thanks for the info

 

Or even 225/40/18 provided that you never take people in your Mini!!

Which I currently have and love !

 

Just put 215/35/18 on my car this weekend and it is a slight to moderate better ride than the 16" runflats I took off.

 

Really, I would think that you'd be feeling the road more compared to the 16's...Hmmm, these run flats really are harsh aren't they