I'm in the process of changing out my winter runflats (Blizzaks) for summer tires. I'd like to kill two birds with one stone by first of all, switching to non-runflats and also raising the back of the car a little without having to make mechanical alterations to the vehicle. Would the 215's make much of a difference? I live in NYC and the roads here not condusive for low profiled MINI's. Any thoughts?
Thanks.

 

You could do it if you want but running wider tires in the rear is going to increase the MINIs already high tendancy to understeer. How about switching to some 15 or 16" wheels?

 

I was hoping not to change the rim size. Not a bad idea though. I already have 4 snows on their own set of 17" rims and another set for the summers. Sounds like, I should stick to the stock size then?

 

DSC starts to get confused if you run different overall diameters front and rear. (ABS/traction control probably get confused also). Not sure if what you are proposing will be enough diameter difference to be a problem, but I have seen it happen.

Jason

 

Why not run 215/45/17 front and back?

 

+1 ^^^

 

How about raising the rear end and keeping the size I already have. As for non-runflats summer tires, can you suggest a tire for normal city and highway driving?
Cheers!

 

It is always better for safety and handling to run the same exact tire on fronts and rears. No mixing sizes and types of tires.

That way you have a predictable and safe car for street use.

Using 205/45-17 is the best choice and you can pick tires that are a little less stiff in the side wall if the roads are poor.

In 205/45-17 if you don't need a really great handling performance summer tire that wears out fast then-

General Exclaim UHP (ultra HP summer tire) $90 each 380 treadwear
Yokohama S.Drive (ultra HP summer tire) $104 each 300 treadwear

Why do you think you need to raise the rear end? Do you carry back passengers a lot or heavy loads? Have you been bottoming out in the rear? Are your shocks old or worn out?

 

I like the look of the lowered MINI, except the streets in NYC are brutal. If I raised the back instead, I thought I can retain the clearence in the front and acheive the sportier look without having to mess with the suspension.

I have an 8/05 R53. Like the run, flats but it's a rough ride at times. I've read the posts here and thought of switching to non-run flats to see if that would soften the ride. One guy I spoke to advised me against that, saying it wouldn't make that much of a difference and suggested keeping the RF's since they were thicker more durable tires.

 

The problem is- what looks good from the outside (lowered suspension) can make the ride quality suffer- depends on all of the suspension changes from stock.

Lowered suspension reduces clearance so the shocks and or springs need to be firmer than stock or the suspension travel will allow your tires to hit your inner wheel well areas.

The stock suspension is softer and so more wheel gap is needed if you are driving on poor roads and if you carry more load/people especially in the back.

A very mild drop might be a compromise- it would look better but not be as severe.

A slightly taller tire size with stock suspension might also be OK but ground clearance height would be a little taller than stock even if wheel gap is reduced a little. Good examples would be 215/45-17 front and back or 205/55-16.

Key to good street ride comfort would be to pick the right tire and tire size to do the job. As ride comfort increases, crisp handling and some performance is reduced.

Runflats are OK for street use but are very firm. Ride quality is sacrificed for safety- not needing to change out the flat in traffic, during the night or in bad weather. Most owners are happy with non runflats once they do change.
The base Cooper has come stock with 15" wheels and non runflats and the ride quality for street use is very good- much smoother than most MINIs with runflats- both 16" and larger.

Performance and handling is a bit better with some of the runflats vs the stock 15" non runflat tires. Better quality aftermarket non runflat tires are easy to find in non stock sizes and offer improved handling, comfort, treadlife, and cost less.

We never recommend running different size front and rear tires under any normal street use situation. Never mix runflats with non runflat tires. Don't mix different tire classes- like summer tires on the fronts and all season tires on the rear.

Don't run tires down to the lowest treadbar- replace when getting near on the most worn tire assuming they are close enough. Keep tire pressure up and rotate tires every 3000-4000 miles for the best wear.
If you don't rotate the fronts they will wear out much sooner and you will have to replace both fronts. If so then move the good tires to the rear and worn tires to the fronts to resist hydroplaning if rain is common in your area.