I have had my Cooper S for 500km now (just as you get to that sweet 4000 revs you have to change gear...talk about frustration!) and the Pirelli tyres (on 17 inch rims) seem to be ABSOLUTELY TERRIBLE. Possible reasons: 1) They take ages to warm up, 2) They're not fit for Greek tarmac, 3) They will take more than 500km to wear in????

As I started gently examining the limits of the Coopers traction I found the front end drifting most ungracefully more and more. I would say that it is bad handling but I also noticed the ABS kicking in on fairly mild braking, so it must be the tyres.

Anyone with similar issues? What tyre options do I have with the 17inch rims other than Pirelli? Do things improve with slightly more or less tyre pressure maybe?

 

Do you have the all-seasons or the sport compound? I don't know anything about tires, but you could try breaking earlier, and powering through the turns. Braking uses up traction. You chould stop it.

 

It's the sport compound. I wasn't referring to braking in the bend of course, I just said that the tyres break terribly even on the straights! Who would want to break on the bend???!!@@!?

The tyres do get a bit better when they heat up (after a looong time). As I said it's a bit early since I am still on the under 4000revs, break in period, but it seems the front end has a nasty habit of losing traction before the rear. It makes me want to yank on the handbrake to let the rear swing out a bit. You guys should come over and try Greek roads - they really are much more fun!

As soon as I finish the break in period I will try driving the Mini more like my previous car (a Citroen Saxo VTS - a bit like the Peugeot 106 Rally) as it seems to have similar characteristics on the bends. Which is what I bought it for!

Other than that, possibly different tyre pressure settings - I will keep you informed.

 

Put 36 cold psi in the front and 38 cold psi in the rear.

You'll get the lighter feel in the rear your looking for when you push it hard in a turn.

Regular driving will be a little firmer though.


Next, I know your going to ask why?

So here is the answer:

The tires are running above recommended pressure of 33 psi ( this is a compromise psi for comfort and handling) for reasons of gaining more traction. As you push the rear even further above recommended they begin to pass their ideal which seems to be guestimated at 36-37psi (general feeling of those on various Mini forums.)

This gives more of a sliding/releasing feeling in the rear in a hard turn. Be careful because you will notice some slight "lift off oversteer" if you come off the accelerator quickly in an aggressive turn (usually longer high speed turns).

Try it before you anylze it. It works.

Some fine tunning is always neccessary to personal taste and "feel' your looking for but the principle remains intact. :smile:


Oh by the way, those Pirellis will follow every blemish in the road. I'm sure you have felt that already.

_________________
Chili Red/white Cooper S

 

Thanx! That's excellent advice and it fits with what I am discovering myself. The more I drive the Mini the more it feels like a Peugeot 106 Rally.

Today, on my regular race to work (a 20km course - about half an uphill climb and half a downhill - constant bends) I really enjoyed myself. I think the question of tyre pressures is slightly different for anyone racing the Mini since you wouldn't want the rear end sliding about as much as I do just for the sheer fun of it. It's not an effective way of getting from A to B fast (I'd probably choose my brother's TT quattro for that), this machine is built for putting a smile on my face!

I have been experimenting a bit with wet driving conditions (no it doesn't rain much in Greece, so I have to play when I find big puddles or something!) and what I am really getting to like is the brakes. I will brush up on my left foot braking and get back to you with more, right after I put a bit more pressure in the rear tyres as you advise.

 

I'm not sure what's available in Greece, but the Falken Azenis Sport is an excellent and relatively inexpensive tire for dry traction and handling. Pirelli has several ultra high performance, but expensive models, the PZero Rosso and the PZero Corsa. The Michelin Pilot Sport or Pilot A/S are good ultra high performance tires as well for all around driving conditions. None of these are run-flats. Dropping down to a 16 in. wheel/tire combo will save unsprung weight which will improve acceleration, braking and handling.

 

Maybe I will shop for tyres next time I come over States-side! Over here the Michelin Pilots have been replaced by a model called "Pilot-Exalto" which is terrible. A shame because they were my favorites.

Your comment about the 16rims intrigues me however. How can traction and overall performance improve? I should think it would be the other way around.

Anyway, the rate I'm going (haven't even finished breaking in yet) I will need new tyres soon - boy they make a noise when I push them to their limits! It sounds like one of those old car chase movies, screeching like crazy...

 

Changing wheel size to improve performance is largely a matter of weight, but there are some other issues. First, the 17 in. wheel/runflat combo that comes on the S weighs 22-25 kg.(52-55 lbs.) each! At the other end, the 15 in. wheel/tire, standard on the Cooper weighs 13-14 kg.(30 lbs.). The 16 in., depending on the wheel and runflat weigh 19-20 kg.(42-45 lbs.). These are mounted weights. The R83, five star 16in. wheel by itself weighs 9.1 kg.(20 lbs) so you can see the runflat tires are very heavy. Some aftermarket 16 in wheels are only 5.8 kg(12.75 lbs.)! Why is this important? A big subject but fairly clear. It takes energy(and time) to accelerate or stop the rotating mass of the wheel/tire; the heavier it is, the longer it takes to accelerate it up to a given speed or brake it to a stop. Your handling may or may not be improved by bigger wheels, for example a 205/50 R15 tire has the same height and wider tread than a 195/55 R 16. Both sizes fit well on the MINI, but the 15 in. combo, being lighter, drives better (I've run both of these sizes). To experiment, try to get a standard 15 in. Cooper set from the dealer, even with the too small tire (175/65 R 15), you will be surprised at how different it feels compared to the heavy 17s.

 

Regarding your immediate tire need: Since you don't have good Michelin models in Greece, what about Dunlop and Continental? The Conti SportContact and the Dunlop SP Sport models are good tires and produced in Europe. Regarding USA sources, one of our best direct sellers is Tire Rack. They sell most major brands at good prices, but I don't know their export policies. Check their website, it has lots of good tire info as well as tire/wheel packages.Tire Rack

 

The Duke is right once again!

Just checked out a review by a Greek car magazine and the Greek BMW dealership gave them a MiniCooperS for testing with 16" and non-run flat tyres....!!!!! The lying bastards insisted that the 17" rims were better when they were selling to me. Of course.

Now to find someone to swap my 17" with their 16"....

By the way they set the CooperS against a Renault Clio2.0 on a race track, and the Clio beat us by 0.9" per round. :evil: If I meet any Clio's on the road I will take revenge...!