I'm waiting to order my new R56, and I could use some help with wheels. With regard to the different sizes, and their effect on performance and ride, could you tell me what you get in the way of performance, and also what you give up in the way of ride and perhaps even fuel consumption by going with the 17" or 18" wheels. Also does larger wheels mean more road clearance? (I suppose this is a dumb question to some of you, but thanks.)

- R

 

Larger wheels do not change clearance because the rubber tire used is less deep to offset for the larger wheel - the outside diameter is essentially the same for all wheel sizes by the time the tire is mounted. Having less rubber on a larger wheel makes the ride harsher and steering more direct.

Too small a wheel makes handling imprecise due to all that rubber between the car and the road. Too large a wheel also hurts handling because the wheel is heavier and the harsh ride affects road contact. A 16-17" wheel seems to be the optimum for handling - get larger wheels because you like the way they look, not for handling, certainly not for improved ride.

 

This is one of those cases where the dumb question is the one unasked.

Lots of folks try to fill out their wheel arches to make the car look good. But there are factors you'll change by going bigger.

1) more tire width = greater rolling resistance (usually) = less fuel efficiency - but you don't have to go wider just because you're increasing rim diameter.

2) larger wheels often weigh more and could result in a harsher ride and inferior handling. compare wheel/tire combined weights of your stock vs. new choices. lighter is better but costs more and alloy rims aren't easily repaired, so a poorly designed or ultralight wheel could break/bend more easily.

3) to keep the speedo/odo accurate, you'll go to a lower profile tire also resulting in a harsher ride and higher priced tires with sometimes with less options

4) consider how picky you are about wheels being clean and brake dust. some rims are tougher to clean than others and some show dirt worse than others (think white vs. anthracite)

5) you probably won't be able to unload your stock wheels to help offset cost of new wheels/tires. Remember runflat rims will take standard tires, but I don't think you can run your stock tires on the new rims if they weren't designed for runflats.

Those are reasons to not change, the upsides are

1) Your Mini will be more unique and more to your liking

2) wider rubber and lower profile tires generally stick better if you buy performance tires

3) if you choose carfully, you could use your spare set of rims for autox or other sporting events.

One very important note is that folks are reporting that R56 may be using different wheel bolt sizes, changing from 12mm to 14mm. Please don't jump the gun and buy your new rims until the wheel dealers get a chance to verify fit to your new car.
We're waiting for an R56 too, and I'd love to fit Flik Wasps (17s?). I think we'll keep our stock rims as the autocross wheels.

 

Word from the UK is that the R56 MINI is (more or less) optimized for 16" wheels. In recent test drives, some journalists asked why the Cooper they'd driven seemed to handle better than the MCS. The response from MINI was that only the wheels/tires were different. Yup, the Coopers had 16s.

What difference that really makes or what one can infer from this is up for grabs, but there are some definite physics at work and conventional wisdom concerning tires/wheels is probably still quite relevant and your best bet. It's just physics. For my money, light wheels (I have 15s) make a huge difference.

 

16" wheels x 6.5 are used on the John Cooper Challenge Cars !!! they are a better drive and give more comfort .I have 17" wheels on my JCW ...they are heavy bumpy ,and you feel every stone ,and pot hole on the road .I treid 18" JCW wheels and did'nt like them at all ...the car seemed to be "jumpy and "twitchy",tramlining all the time .I have driven a GP on a number of occations with the 18" wheels ...that car seems to be better set up and runs and drives like a dream . At the end of the day 17" wheels do look better than the 16" ones ( if that's what you want ) and you'd get used to driving with them on . The wheel size will make no difference to the road clearence at all you need to lower the car for that .

 

I think the GP's suspension was re-engineered for 18" wheels similar to the comments made by Gokartride about the MINI's default handling being configured for a 16" wheel. I know the suspension was tweaked on the GP to have a more composed ride.

 

The first MCS I test drove 3 years ago had 17" S-"lights" (an oxymoron) and it felt like driving a gravel truck; then I drove an MCS with the 16" standard wheels and it was like the difference between nite and day, so I wnet with those. Now that my RSCs are approaching replacement, I'll prob go with conventional performance tires--simply lighter, and that's one performance upgrade that works, lighten your unsprung weight

Also, the Rover monkeys never really bothered to optimize the suspension for runflat tires, and I guess that is one issue BMW addressed in "refining" (God there's that awful word again) the S. Also, I think the sport suspension option on the R56 is the same setup as on the GeePee. Could be wrong tho.

 

Rover Monkeys? I thought that Rover Engineers created the new Mini that we all love, not monkeys. A little respect for the folks who worked to create these cars.

 

sorry Karl, but having owned other Rover products I have zero respect for their engineering capabilities. most of the problems with the first gen car can be traced to Rover designs and engineering (like all the interior parts and body integrity issues that have cost me 9 shop days to get addressed) and the only respect I have is for BMW knowing what a liability Rover could be and dumping them off to Ford--but keeping the MINI name. One of the smartest automotive moves ever.

That's why I'm so excited about R56: it is BMW's car, lot, stock and barrel, and I expect it to be a much superior car.

 

Thanks for all the info! I'm now thinking I'll get the Webspoke 17" wheels. I'll be getting the sport suspension, LSD, DSC, and JCW brakes as well.

I love the Cooper for its handling, so I don't want to compromise that, but it seems 18" may be a bit too rough for everyday driving. This will be a commuter car for the most part.

-R