Who's been running a 7.5" wide Kosei K1 wheels or similar 7.5 wide 17"s? Seeking impressions/experiences with various tires.

Context:
Early '03 (late '02 production) MCS with non-moded OE sport suspension.

Goals:
Keep the razor-like steering & solid feel of the runflats, but lose some of the harshness.

Absolutes:
- No runflats
- Only 17"
- Don't care about matching OE spec for sake of "correctness"

I've ordered a set of Kosei K1 Racing 17x7.5's... But am on hold because the tires I'd wanted are out of stock. At this point I'm almost glad, as I've been wondering whether or not I'd be happy with my choice.

Considerations:
Wondering how much the extra half inch of the 7.5" rim will stretch the tire...? Will the OE 205/45 aspect ratio stiffen up the non-runflat enough to capture the knife-edge repsonsiveness of the runflat...? Or will I need to go to a 40 series apsect ratio to stiffen the sidewall in order to gain the level of responsiveness experienced with the runflats?

BTW
I realize that a wider (e.g. 215) tire won't have as crisp a turn-in as would a narrower 205. Nonetheless the decrease in aspect ratio would make prudent an increase in width (to protect the wheel). Even with a 215/40 there would still be a 3% loss in tire volume compared to the 205/45.

TIA for your thoughts & suggestions

 

I never thought the runflats had knife-edge responsiveness whether 16" or 17". It was OK but nothing really to write home about. Excellent non runflat tires can offer better performance if you find the right one in your price range.

17x7 or 17x7.5 doesn't really matter that much for the tire sizes you are considering. Assuming wheel offset is not extreme both can work with stock suspension. The 1/2" difference is not a problem.

For 205/45-17 did you check out the Dunlop SP Sport Maxx $141
240 treadwear AA traction W speed rated 20 pounds Fits rims 6.5-7.5"
$100 rebate when you buy four dunlop tires from Tirerack.com
Good test results vs Potenza S-03
http://www.tirerack.com/tires/tests/...ay.jsp?ttid=59
In stock at tirerack- talk to Alex.

Also available in 215/45-17 ($120 special/ low stock) and in
215/40-17 $161 21 pounds Fits rims 7-8.5" perfect fit for 7.5"
This tire has the same tread width and a 1/2" more section width than the 205/45-17 tire of the same type.

Which tire did you want that was not in stock?
For the price the Sport Maxx in 215/45-17 looks good or in 205/45-17.
For street driving the 45 series tires will be more comfortable and forgiving. 40 series is pretty rough on all but the smoothest roads.

 

what offset are those wheels? i know someone that needed to use spacers to accomodate for the clearance against the strut.

and as far as tire width goes... well, i have 16x7's and im running 235/40's. steering response is better than the 17" runflats. im sure you'll be happy with 215s

 

The runflats are SO DAMN FIRM that input (to the steering wheel) translates almost instantaneously to directional change - not much flex or bend... whether input is a flick of the wheel between lanes, or a higher 'g' turn the sensation of response to driver input is most decisive.

I know there's more to tire performance than sidewall behavior, but at the moment THIS is my focus. I'm confident that IF I can get a tire with a sidewall which performs closely to that which I've grown accustomed, other aspects of performance will be fine.

EDIT: What would concern me would be if the 7.5" were to stretch the tire such that I'd be back to the runflat's total lack of compliance.

Hopefully this clears up the differences in perception/ language.

215/45's are the exact tire I'd wanted, and its out of stock - EST- mid April - I'm considering all of the sizes above.

Thanks for the thoughts

 

Offset is ET 42. As I'd said, I already have a set of 215/45R17's & they're mushy feeling. While I appreciate the whole road noise/ride comfort thing I'm reluctant to give up the slot-car drive... and that's what's going on with the current tires.

Cheers!

 

mushy, huh? hmmmm... what kinda tires are you running now? how's your tire pressure? i personally think that any regular tire is cushy-er than run flats, but sidewall stiffness will vary between brands. good luck with your new setup

 

Agreed, thanks

Please recognize this is in specific reference to 17" tires on the MINI... not a contrast to the way other tires/cars drive. Current tires are non-RF version of Dunlop SP9000. I tend to run 35 to 36psi.

 

215/40/17 DO IT

 

You got em on your ride? If so, which rubber?

 

I have the Kosei K1 17's 45mm offset with GoodYear F1 GS-D3's in 215/45-17 non run flats. Car came with the 16" all season run flats I use for winter (sometimes). The 17" non run flats give a better ride and better handling & grip compared to the 16" OEM fun flats. But, the 'rubber coated rim' feel in the wheel I felt in test driving a S with 17 run flats is not there.

I suspect to get that back I'd also have to take back the bone jarring ride on my daily commute. (Concrete road with expansion strips). My commute was bad enough on the 16" run flats I can't imagine what'd be like on the 17" runflats. I'd be happy to settle for it in the rest of my driving but the road to and from work and it's big expansion strips are like a worst case scenario unfortunately.

That S (hardtop) I test drove felt like it had solid rubber tires. Amazing feel in the wheel but it was all glass smooth road around there so I didn't get a feel for harshness on that drive.

I assume the super stiff (run-flat) low profile sidewall is what gave that feel, and would also give me the bone jarring ride back. But, I have a MCS convert which was only available with the sport suspension, not sport plus that the S tintop had. So I have a bunch of other variables.

When I ordered the convert I was assured it had the same suspension as the car I test drove. Turned out to be wrong, the S tin top had the Sports Plus.

I think however that the feel in the wheel 'slot car like' as you put it is more likely tires than springs or sway bars. I think that because I noted that great feel even at 10-20 mph just navigating a parking lot. I doubt the difference is 215 vs 205 or a 45 vs 40 sidewall would make the night and day difference I note. SO I'd caution you if that feel is your #1 priority...

I really need to drive some other MINI's and compare setups.

I'm totally happy with the ride and performance of the F1's, the only thing missing is that 'feel'. The feel is still better with my current combo than any other car I've owned but or even this car with the 16" runflats, but...

 

Hey thanks for all the words mmatarella, its always interesting to hear other MINI owners experiences & impressions

I've got what you're calling the Sport Plus - whatever the most firm offering was at the time. I've also been on the s-lites (what an inappropriate name) until just recently.

Your 'rubber coated rim' comment is about right Certainly has its pros & cons. On smooth pave its the most connected fun-filled ride. On bumpy or pot-holed roads its a bone-jarring slalom of unpleasantness. But I've lived with it this long and only recently switched to non-RF tires. Thought I'd appreciate it more than I do.

I've driven other MINI's, and currently am running on a set of 16" conti RF tires. The 16" conti's are better than the 17" RF's for harshness, but then they lack a bit in cornering - IMO not getting best of either world.

At this point I'm pretty sure I won't be going with the 215/45's... The 205/45 would be a no-brainer... but the 215/40 option is growing on me.

Who's running 215/40R17 on Kosei K1'S? - Anyone?

 

Anyone else have experience with these wheels/rubber in 17"?

TIA

 

I have K1s and Falken RT-615 215/40/17. I have put about 14000 miles on them including track days. They are great tires and I am leaning toward replacing them with the same, especially as they lasted longer than I thought. I am running -2 camber front and -1.5 rear, so tire wear is a problem that makes the relative long life of the tire even more impressive to me.

 

Thanks DrPhilGandini

How would you rate the feel vs. OEM for stiffness? Have you ever wanted or considered going with the stock sized 205/45R17? Were you on S-lite runflats to start out, or other? Whether or not S-lites with runflats, how would you compare turn in with the wider tire to what you had OEM?

Thanks again for the details, including the camber - much appreciated

 

I love 'em. The ride is better than RF's, though I would never describe it as mushy. I run 35-36 psi with stock '05 suspension.

I agree that the sidewall height and construction are a major factor in both handling and ride. But, I don't have the luxury of super smooth pavement. And, I don't have the tolerance for crashing over rough pavement in a daily driver. That's why I chose both a bit more width and aspect ratio than stock. At the same time, the Goodyear's offer great performance with acceptable (IMO) comfort.

After reading through this thread quickly I can't recall the brand/model of tire you have on order. Suffice it to say, the right tire choice is about much more than just the sizes.

I know you know that, but to illustrate the point, consider an extreme example: Compare a top-of-the-line Max Performance summer tire to a high performance "bargain" tire of the same size. The difference in steering response would be dramatic. Now compare two different sizes of the same Max Perfromance tire: The difference in steering response would be much more subtle.

I know all this is pretty obvious, but I'm constantly amazed at the choices people make when it comes to tires. Given the high priority you place on steering response, I think you'll be very happy with your 7.5" wheels, especially if you mount up some really sticky tires. There are a lot of good choices. I'm tickled with the Goodyears, but I'm tempted by Michelins and Bridgestone Ss-03's. Yokohama has a new offering that looks great too.

Since ride takes a back seat to handling in your priorities, you should have no trouble finding a tire that will fill the bill. It's been said before, but give Alex@TireRack a call. And let us know what you end up with.

Happy motoring!

 

I ran S-Lites with Dunlop RFs. I didn't spend much time on them, maybe 2500 miles, but the RT-615s are much better all round--stickier, better turn in and grip, they don't seem to squeel at the track, and have predictable slip. I have driven in the wet, but would rate them fair-weather tires. They do ride "stiff" but in a racing-tire way, not a harsh, no feel way, if that makes sense. I have HSport springs, and the tires are quite low profile, so rough roads are pretty annoying, and I bottom occassionally. I have camber plates and a M7 STB to reinforce the shock towers as mitigating factors.
The rims are very close to the front springs -- I'd say 1/4" but don't ever seem to have hit them. Also, even though the rims are cast and have very slim spokes -- you'd think they would flex -- I run Wilwood 13" BBK and have never had the rims touch the calipers, so they are pretty rigid rims. Randy Webb ran them on his racing Mule for quite some time.
cheers,

 

YES

Thanks for the added The K1's seem very sturdy indeed, your experience (lack of flex) is very positive to hear. Reinforcing my sense of good purchase

 

Also have Kosei K1's with 215/40's..........love them. Went to these from stock S-lites which of course weighed a ton more. I'm runninig General UHP Eclaims which is an all around tire, not a serious grippy tire. And they are also a great bargain at about $70 each if I remember correctly..