I have a set of barely used JCW rims in my garage, waiting for the runflats on my 17s to go.

I am going to be getting the JCW brakes on next week, and at some point in the near future want to get the JCW rims on. Called the dealer and was told that 205/40 18 is the size tire they recommend for that rim. There is a pretty bad selection of tires that size in the market. Dealer also said that they have seen lots of problems with the JCW rims getting bent, and the shoulders coming off the (non RF) tires from potholes, etc. due to the small sidewall it has...Now I don't know what to do. I am NOT into Auto-X, I like the look of the JCW wheel but don't want RFs due to the harsh ride.

What size tires have any of you used on the 18" JCW rims? Is the 205/40 18 the ONLY size that will work? If any of you have used other sizes/brands that you would recommend please let me know - and also mention if you needed the wheel stop installed with them or not...

Thanks!

 

I've got about 10k city-highway commute miles on 205/40-18s and love them - Toyo Proxes 4s - an awesome AS tire in that size. I'm thinking about going to 215/40 for the replacements, to take a little edge off the ride and quiet it down a tad. 215/35 would also work on 18x7s. For the price you could probably get for your JCW rims, you could buy a set of much lighter new 18s and tires. I run OZ Superleggeras, which can be had now for less than $200 a piece as they've been discontinued. About 17lbs and very strong. And they look fawking hawt.

 

205/40 PS2's Rock

215/35 works as well on OE wheels

Alex

 

Alex - I assume you mean that PS2's rock your back account.

What about 215/40? That's only slightly taller than OE. Any issues with that size?

 

24.7 is a taller than I can promise to work, but its reasonable close.

Alex

 

Thanks, guys - XAlfa, I got my JCWs used for a mere fraction of the cost new, like the look and don't care as much about weight - so I'll stick with them, but do appreciate your suggestion. (Ahem, if I'm going to play on your Team Craptastic isn't it heresy to suggest other rims than JCW?)

Did you get your Toyos in the Bay Area? Maybe you could educate me a bit further - you sort of implied that 205/40 tires run a bit harsher than 215/40 - what does the "40" mean? And how does that translate into ride comfort? Is a "35" tire more or less softer a ride than "40" tires? Or are there other variables to consider? Basically, I would to get as smooth a ride as possible on 18s...
Did you have to get steering stops with your 205/40s? Would the 215 tires work, or be more of an issue with turning?

Thanks for the help!

 

First, I'm no expert. That would be Alex...

40 refers to the height of the sidewall as a percentage of the width. So a 215/40 has a slightly taller sidewall than a 205/40, which should soften the ride a bit, all other things being equal. I'm sure there are differences across tires of the same dimensions. I know runflats are significantly harsher than conventional tires of the same size. I have no steering stops and no issues. My sense is that is an **** BMW thing. I got my Toyos slightly used mounted on a set of wheels, but they are available from Edge Racing for a pretty reasonable price.