205/45R-17
for an '06 Cooper S JCW.

anybody got any experience with this tire? looking to improve ride and decrease noise while not sacrificing too much handling over the summer performance tires i got OEM, which are toast after 18k miles.

 

and is there any real reason to go up in size to a 215/40 or 215/45?

 

Had 'em on my 03 in 215/45. Only reason I got that size was that's what Discount had in stock and I needed them Right Now!. Ride quality was much improved over the OEM Euphori@s without giving up too much in the handling dept. They will not make you "run faster, jump higher", but they are a good tire at a very reasonable price.
They are, however, only "H" speed rated, so take that into account.

 

I got the 205/45R-17 about a month ago and so far they are pretty good damn tires for the price.

I do have mushrooming but not related to the tires just bad %^&*(ing roads.

 

what about the kumho ecsta asx or spt (non runflat)?

both are in my price range and offer z rating.

 

i just got 205/50 16 kumho ast on my R56. they are great tires, much better ride than my 17 inch dunlop runflats. turn in is a little softer due to softer side wall, but progressive. i am really happy with the switch.

 

Had 'em, liked 'em, wore them out, and moved up to the Kumho MX Summer Performance tire, which is much better and worth the extra bucks.

 

The SPT's are great tires! Good balance of performance versus ride. They are no good in snow though. They aren't a high performance summer tire, but they are one of the best tires in the rain. In fact, they are a popular choice for "rain tires" for autocross use here in the Northwest.

I'd get the SPT's unless you plan to drive in a considerable amount of snow. They will squeel in the occasional high speed turns much less then the ASX's because the SPT's have wide tread blocks.

 

I have the ASX 215/17" all season. Can't complain, other than they're wearing out quickly too (too many curves around here ).
My track tires are narrower (just wanted the wheels), tend to roll over onto the sidewall, and don't look right.

 

Wider tread blocks (like the SPT's) will greatly help with wear under spirited driving, but unfortunatly wide tread blocks don't work well in the snow.

The problem is that the small tread blocks (especially the little cuts called syping, that really help on ice) will roll over and tear. That's why they wear so quickly.

It's common knowledge in the autocross world that sticky maximum performance summer tires will last longer on an autocross course than harder all-season radials with a much higher tread wear number. Again the problem is with the small tread blocks tearing instead of wearing.

 

I bought the ASX for my '03 MCS Works, and I like them so far. I even took them to track day at Heartland Park with no exceptional wear noted , which means either they hold up well or I wasn't driving hard enough!

I can report that they're an excellent rain tire as it's been raining cats and dogs around here all month, and they are absolutely the quietest tire I've ever driven!

I bought 215/45 -17's from Tire Rack, seems to be a common size and they were very reasonably priced. (Sorry Alex, I didn't know we had a rep at Tire Rack when I bought them or I would have called you - Damon took good care of me tho)

 

205/45-17 is the stock size and is based on using runflats and the preferred design of the MINI suspension engineers.

You can use-
215/40-17 but this is less tall than stock so you get some speedo and odometer error and larger wheel gap if you have stock suspension. Lower sidewall is stiffer and ride quality is harsher but it depends a little on which tire selected. Tire variety is large but more towards higher performance and prices are usually 10-20% higher than 45 series tires in 17".

215/45-17 is a good alternate size but it is a little taller than stock by about 1/2" which works fine for stock suspension but might rub a little in the back against the inner plastic wheel well (might need a little trimming). This size offers a very broad range of tires suitable for performance or for comfort or both. It is wider so it's not the best choice in all season tires for use in the snow. Decent handling and good comfort possible, may depend on which tire you pick.

225/45-17 is larger than stock (25") will fit with stock 17" wheels but not enough clearance if you lower your car more than just a little. Wider and taller so it's a heavier tire. Tire selection very large from higher performance to good comfort. If you match it with wider wheels you have to watch the offset of the rim to get it to not rub. Look for about +45mm offset rims.

For Kumho Ecsta tires-
AST (KU25) (High Performance All Season) (ranked 12 of 21 tires in class)
http://www.tirerack.com/tires/tires....odel=Ecsta+AST
205/45-17 $68 each 400 treadwear H speed rated 20 lbs 24.3" tire diam.
215/45-17 $66 each 400 treadwear H speed rated 22 lbs 24.6" tire diam.

ASX (KU21) (Ultra High Perf. All Season) (ranked 7 of 15 tires in class)
http://www.tirerack.com/tires/tires....odel=Ecsta+ASX
215/45-17 $86 each 420 treadwear W speed rated 21 lbs 24.6" tire diam.

SPT (KU31)(Ultra High Perf. Summer) (ranked 6 of 45 tires in class)
http://www.tirerack.com/tires/tires....odel=Ecsta+SPT
Comes in
205/45-17 $93 each 320 treadwear W speed rated 21 lbs 24.2" tire diam.
215/45-17 $84 each 320 treadwear W speed rated 22 lbs 24.6" tire diam.

MX (KU15) (Extreme Performance Summer) (ranked 3 of 4 tires in class)
http://www.tirerack.com/tires/tires....Model=Ecsta+MX
215/45-17 $112 each 220 treadwear Y speed rated 21 lbs 24.7" tire diam.

Given this-
If you have to use the stock size then pick SPT
If you don't mind 215/45-17 then consider SPT and ASX for best value with solid balance of good wet and dry handling and good comfort.

If you want best dry handling and don't mind faster wear then MX is good.

Between SPT and ASX-
SPT has more aggresive tread and wears faster, it is not for any snow
ASX wears well, is all season and offers solid handling and comfort.
I think the 215/45-17 size will work fine for you.

 

well i went with the asx, in 215/45-17

first impression (based on a 10 minute drive home) is WOW do runflats ever SUCK in ride comfort. felt like a new car in terms of suspension compliance. already happy in terms of accomplishing my goal of making it not a brutal ride over potholes and bad roads. now if feels smoother and more sophisticated, not like a kids hot-rod with stiff shocks that bash over every expansion joint.

i think i noticed a bit more sidewall flex in a loss of crispness on turn in, but haven't acually steered enough to tell if it's a problem or just a difference.

oh and they make a much lower pitched chirp when i grab second and third than the dunlop dsst OEM rubber (bald now) that they replaced.

lol

 

I have the Kumho Ecsta MX at 215/40X17. Great tire and one of the favorites for BMW club racers. It's no longer the King of the Road but pretty close to it. 215/40s are just a tad smaller that the 205/45. At 70mph the GPS read 70mph and the speedo read 72mph...It's about 2mph across the board. It's really a nice upgrade as the 215s are quite a bit wider and fit nicely on the stock 7" rim.

 

I have the 16" [205-50] ASX and really like them over the runflats I had before...just a smooth riding tire. Took them to the Dragon this weekend and they held up well, although they were a bit underinflated [32 psi]. We came home today and I added air to 36 psi for the ride hoem...what a difference. makes me wish I had had the foresight to have done that before going Dragonslaying.