18" wheels

[simplygriff]

It's just gonna depend on the offset. The Mini's have a pretty high stock offset so you'll need to keep it somewhere between +40 & +50 unless you want to stretch the tires. I can't help much with tire sizes though cause I've always had 17's. My wheels are 7.5" wide with a +45 offset I believe...
-G

[MINI Rog]

I was in Flow last Friday and they had some 18" take offs in the parts dept. They were JCW wheels complete with brand new runflats installed they offered them to me for $1,500 (about half price). I didn't need them that bad but you might want to give them a look.

[surreptitious]

Hello to all,
I am in the same situation of looking for the tire size
To fit on the rims I current have, six SSR GT1 rims, these rims are no longer produced, a couple years ago, four (retail) about $1500, Now, Used Ebay (six for $201). Well the rims are the 4x100 bolt pattern; 18x7.5 offset is +40mm,
Here's why I giving you a little back ground.
Based on the rim size and offset, and which tire you consider, 215/35/18, seems to be the widest, however each tire company has there own measurements, so Goodyear 215/35/18 might be smaller or wider then a Dunlop tire or any other company that makes a 215/35/18. It gets to be tricky; some have mounted 225/35/18 and fit in a stock, suspension setup.
Also the offset and width play a large part in the setup you want, cool factor any 18" rim is great, mileage, Xcross the weight of the rim is something to consider, and the quality (strength), and then there's the ride quality, with the lower sidewall and the run flat, which make the ride really rough (stiff),, if one or both, again the larger the tire weight, less mileage, possible slower response, but better tracking. Another consideration is if you plan on lowering the can with the proper suspension, adjustable coil over or lower springs, in which you will need to buy front caster/camber plates for the front alignment, and adjustable, rear arms, (four) to also adjust the rear alignment, if you don't the tires will wear out oddly and fast, and the tires are not cheap. Tire Rack is great to answer a lot of the questions on the tires and rims. Also looking out NAM and other Mini forums will help with others who have done various 18" 19" 20" rims and tires. but a lot of reading is necessary to get the info you looking for.
Okay, My plans for my research on my 03 S, are to extend the rims out from 40mm to 45mm or 50mm with some H&R spacers (5mm, 10mm, 4x100), to push the tires out to the maximum, but still be street legal. Mount 4 215-35-18 Pirelli P Zero Nero tires, these are name brand, rated very high, and are the lightest 18" tire that I am aware of (lighter then a lot of the 17" tires. To my SSR GT1s. I believe these are the second or third lightest 18" rims I can find, especially for the price I got. (Also a lot lighter then a lot of the 17" rims). My goal is to have a good balanced street, Xcross, performance, coolness factor. All on a budget. (EBay... Gotta love it).
I hope that helps, any views, comments, suggestions are welcome.

[HPUdrew]

Just a couple of comments about the last post...

If you add spacers to push the wheels out, you are actually lowering the offset of the wheel.If you take an 18x7.5" wheel with a +40mm offset and add a 15mm spacer to it, you are actually running a +25mm offset, which would stick out on our cars. You can't add offset to a wheel, only take it away.

Have you test fit the wheels yet? It sounds to me like you have the correct offset for that size wheel, and that most 215/35-18 tires should fit just fine, especially if you do not modify the suspension any. You should be able to find out the section width of every tire through their website.

Drew

[surreptitious]

Hmmm.... HPUdrew, I thought about it, took your advise and test fitted the wheel tire combo. 215-35-18 Pirelli P Zero Nero tire and SSR GT1 wheel, Your died on, I stand corrected, no spacers needed, I believe it's pushed out the furthers point (still being legal for street).
I believe I got the spacer idea from adding the 5mm or 10mm spacer to a 17 x7 to get a 50mm, I did not take in account the 18 x 7.5 (1/2 inch), so the 40mm setting with the 7.5 rim, made the difference. I have a set up front and am going to test drive them. Thanks for your thoughts, saved me from wasting money on spacers and extended lug bolts.
I am thinking of lowering the car with adjustable coilovers, front camber plates, rear adjustable arms, with the 18" rims and tire combo discussed above. The next question to anyone that have lowered the car with 18" wheels, Some people had to go back to 17" , I believe because of clearance and steering issues (rubbing while turning), I am aware of the JCW steering limiter. But wanted to get any views, comments, suggestions. A lot of thanks to HPUdrew. :)

[simplygriff]

If you go with 18's and the proper size tires shouldn't you essentially be keeping the diamater of the wheel/tire the same as stock? Thus, no rubbing issues if your offset is correct. I had rubbing when I changed to 17x7.5's but it went away once I dropped on H-Sports. Just my $0.02
-G

[HPUdrew]

215/35-18s are actually slightly shorter than stock 205/45-17s, so you would think that there would not be an issue. A lot of times it depends on the profile of the tire though. If you get a 215/35 that has very flat sides, or the edges aren't rolled, then you could run into issues. I think the Goodyear F1-G3 is supposed to have a very flat profile. This gives it a great contact patch, and the flat sides benefit handling also. At the same time, it is much more likely to rub than other tires of the same size.

That is also why you stopped rubbing once you dropped your car. You would think that a lower car would rub more... but the negative camber pulled the tops of the wheels in enough to keep you away from the spots you were rubbing on before.

I love this kind of stuff. :D Glad I was of some help bintliff25.

Drew

[surreptitious]

There are Pics in my members galley (bintliff25) of my test fitting,
of a SSR GT1 18 x7.5 40mm back spacing, These are the third lighest wheels that I know of at 18.5 lbs, The Tires Pirelli P-Zero Nero M+S 215/35/18 at 19lbs each Lightest 18" tire that I know of. These are spares that I have been test fitting and playing with the possiblity of black wheels, They fit Great and no rubbing. But I am Considering 215/40/18 to correct the speedo being off (from the factory as much as 5 -10 Mph).
Any thoughts , views, comments are welcome....

[simplygriff]

Have you seen this?
http://www.eunos.com/tirecalc/

It can help out immensely.
-G

[surreptitious]

Thanks, simplygriff
For the Tire Calculator, This is great
RE: http://www.eunos.com/tirecalc/

Upon investigating the tire size for the 18" wheel, I found that some folks run the 215 40 18 and others run the 215 35 18.
The 40's are slightly taller then the stock 205 45 17,
I believe the JCW 18" wheels are mounted with the 40's
And have a softer ride; I believe slightly taller sidewall will give a little more flexibility. This should work fine with stock suspension, but for those who have lowered there cars the 18's with the 40's did not clear, but it could have been from the rounded or squared side wall, or the way the various combination of aftermarket lowering setups, i.e.. Lowered springs or coilovers.

The 35's are a little lower and give lower stance, stiffer ride, because of the lower sidewall, this is just slightly lower then the stock 205 45 17,
Since I plan on putting the coilovers on, it?s a safer bet to put on 35's.

I did notice while testing the 18 with 35's combo, while lane changing and going over the reflectors on the Interstate, The bump fell seem to hit harder and was much more pronounced. But the Feel of the road was greater (being smooth).

The other and costly issue of lowering with springs ($100 to $200) or coilovers ($800- $2000), and the cost of Front and Rear Adjustable Caster\Camber plates for the front ((under tower mounted )H-Sport or Helix $500) and the 2 Pair Upper, Lower of Adjustable Caster/Camber Rods ($400 to $500). All Retail Prices, but being patient and checking the various Mini Forums, and eBay,
I believe I should be able to all the items for $800 -$1200.

The 18" wheel on a Mini look great (IMO), And create a unique look,
Thanks for the advice, views and thoughts. I should have mine on soon.