After much debate I ditched the worn Dunlop 5000 run-flats on my '03 MCS last week and bought some Falken Ziex 912's in 205/50/16. Initial observations were:

-much better traction
-only slightly softer ride
-handling ok and more predictable

this was after a fews days of in-town driving; now, after a week of all-around driving, I have made another observation:

-car handles like crap

Basically, as the speed increases, the handling gets worse. I took a highway offramp at the same speed as I usually did with the runflats and it felt like the back end of the car was dancing to a different tune than the front. Taking a round-about at a speed that would, with the run-flats, have sent me through nice & flat now resulted in the car porpoising as well as seemingly swinging side to side about its central pivot point.

Now obviously there are some differences in handling to be expected when changing from a tire that has such a stiff sidewall that it can support a car with no air in it, but this current level is unacceptable. I am guessing that this has to do with both the tire choice (too soft, not high performance enough, all season) as well as size (need to go to at least 205/45/17).

My question is this: if I switch to a UHP summer (or all season?) non run flat 205/45/17, will the positive handling aspects that I enjoyed with the run flats return? Or will a non run-flat always be slightly mushier unless I go to a very low profile (i.e. with an 18 inch rim)?

Is there a piece of the puzzle I am missing here?

Any constructive advice most appreciated

cheers

greg v.

 

There is always going to be a difference between the run-flats and convention tires in initial turn in and feel. As you stated this is just a side effect of the stiffer sidewall.

I don't have any experience with the Falken's, but when I went from my Pirelli's to the Goodyear F1's there was a bit of a handling change but nothing like you are describing. After the initial impression of worse performance I actually noticed that the tires were more predictable and forgiving along with a much improved ride.

Have you rode in a MINI, or driven one, without the runflats to compare yours to?

 

I've been using 215/45/17's for four years now and the handling is fantastic.

 

Also if the tires are new you’ll have to drive them about 600 miles to get all the oil from the injection mold worn off.

 

Have you checked your alignment specs?

Any other mods to the suspension?

Made sure the tires are inflated properly?

You don't state where you are from but here in Texas we can swing from a 70 degree to 40 degree day overnight. Tire pressures set on a warm day will be to low on the colder day and could cause some of the issues you are experiencing.

How many miles are on teh new tires, they do take a few miles to wear off the mold release compounds that can create a greasy feeling.

 

As the others have suggested, check your air pressures. This greatly affects the handling of your car no matter which tire type you are using.

 

thanks for all the responses guys

tires are set at 40psi, per the shop that installed them; seems high to me, what do you think? I know that stock is between 32-36 psi. I am in Vancouver, BC, and since the tires have been on it hasn't dropped below freezing. I have only put about 100 miles on the tires, but the initial slick feeling is gone, and as I stated earlier the grip is really fantastic compared to the run-flats.

Suspension is completely stock, car has about 34,000 miles on it.

ScottinBend I agree, the tires do give me the sensation of being more predictable and forgiving, along with the much improved ride; if I can figure out the current issues I would be much happier with them than the run-flats. Unfortunately the only other Mini owner I know is still on run-flats, but perhaps my dealer can hook me up with a loaner or something so that I can have a basis for comparison.

cheers

greg v.

 

40psi is a bit high. I run about 36 front and 35 rear.

 

Call Alex at Tirerack. He often appears on these pages, and is a good guy who will steer you right.

Be glad you ditched the run flats. Terrible tires!!

 

+1

 

So, if I'm reading things right, you went from a summer tire with 280 UTOG rating to an all season with a 360 rating. I would expect a pretty huge difference in handling just from tread compound.

IMO it doesn't start to get fun until you hit 200.

 

hello Tazio

actually the original tires were the Dunlopp SP Sport 5000A DSST UHP all seasons, if that makes a difference. They were terrible in the wet, and as my bro says my face was constantly lit up yellow by the traction control light coming on every half second or so...

So basically I switched from run flat uhp all seasons to non run flat uhp all seasons.

I put a few hours on them yesterday, trying to get them to act up, and they did seem better; maybe I just need to get used to them? One of the odd aspects of the new tire's handling may actually be the way that they respond to power application through corners; I did notice a strange sense that the tires were surging side to side in response to lots of power application, or at least thats what it felt like.

I will probably switch to 205/45/17 at some point, but for now these tires are still loads better than the run flats, and I just picked up a Slime Smart Spair kit, thanks to all those who pointed that one out.

cheers

greg v.