Remember that smile you had when you first bought your mini, how exciting it was to drive, I do, now, after replacing the run flats with Michelin Pilot super sports. I was convinced in some sort of way that my tires were fine, I was wrong.

If anyone is on the fence with regards to changing out from run flats to something else, take my 2c of advice, toss them.

That is all,

Thank you as always for this wonderful source of information

 

I can't wait until I wear out my tires or "accidentally" damage a couple so I can get into a set of non-runflats.

 

Funny how I feel the opposite. Once I replaced my runflats with the exact tire you have the Michelin Pilot Supersports I lost cornering, and gained tram lining on the freeway.
The go cart feel is not the same as it was. I know I am in the minority and everyone hates runflats but I do not.
We should have swapped tires and saved both of us money.

 

You need a bigger rear sway bar

 

I ditched the noisy runflats a couple months ago and have never regretted it. Those things sucked -- at least from a "rolling around town" perspective. I haven't really noticed any change in "performance" driving, but I don't rally my car or anything.

 

I've been reading posts on tires, because I am not willing to pay $400 per tire for run flats, especially when I go through them so quickly. I guess I'll find out which I like more!

 

I have a set of nearly new Bridgestone run flats size 205-45-17 for sale. See details on the tire and wheel section for those that are interested at about one fourth of the most quoted above. They are as new.

 

I have noticed since switching to non run flats, my mileage got better. This must be due to the fact that non run flats are lighter, right?

 

A pre-apology for hijacking this thread, but I just replaced my two rear tires with some decent Continental high-performance all seasons, only to discover that the tires I was replacing were Continental run-flats. So now I have two run-flats with about 30-40% tread left on the front, and two brand new non run-flats on the rear. The handling is dreadful. The rear of the car always wants to lead the front and it feels like I am driving on ice in the rear. A simple lane change on the highway gets the back end squirrely, and invokes the DSC for a few seconds. A cloverleaf on the way to work taken at average speed (40 mph) permanently lights up the DSC light, and causes the tire pressure monitor light to come on. I have to shut the car off and back on to reset the lights.

I know new tires have a short break-in period (500 miles or so), and I know there will be more tread squirm on the new tires, and I know the run-flats have a stiffer sidewall, but it can be a bit scary to drive. I know I should have replaced all four tires with non run-flats (money issue), but could these issues be caused by the tire mis-match? All tire pressures are identical, and the suspension all seems to be OK.

I am thinking about switching and putting the new non run-flats on the front to see what difference it makes.

Thoughts? Opinions?

 

The consensus between tire manufacturers, automobile manufacturers, customer feedback and real life experience is that mixing run-flat tires with non-run-flat tires often causes very unstable handling. This is especially true at highway speeds and when making turns with the vehicle, even at moderate speeds.

http://blog.tirerack.com/blog/make-d...ead-this-first

 

Thanks hsautocrosser. That's what I get for not doing my research before buying, especially since I bought my two tires from The Tire Rack. My mistake was not being aware that the tires on the car were run-flats. My excuse is that I bought the car from a dealer who had put new tires on it, and I never thought a used car dealer would spring for the $$$ for run-flats; my experience has been that they always put whatever the absolute cheapest tire they can find.

I am still going to switch and put the good new tires (non run-flats) on the front, to see what happens, but I definitely can confirm that you should not mix these tire types. I will report back (maybe tomorrow) on what, if any differences I find.

As an aside, I ran a local autocross this past weekend with the two different tire types, and on-course, the car actually did pretty well, felt well-planted, but with a little squirm in the rear. So apparently, at 8/10ths+ driving, the tire mismatch was not nearly as noticeable as it is at anything below that. Very interesting.

 

I bought 4 Kumho Ecstas last summer, took them off for the winter while I ran Pirelli Snowsports and put the Ecsta's back on - they're already toast (burned off the inside tread, especially on the back wheels). I do like the non run-flat feel but would have liked a little more wear out of the Kumho's. I figure I have only 15K on them.

 

If you turned the traction control off during the autocross that may have accounted for the improvement.

 

Another great point, and I did run with the traction control off, although it still felt a bit like a pendulum, with the rear trying to swing itself around when entering turns. As soon as I got back on the power, it straightened itself out, but still felt funny.

UPDATE: Two nights ago I swapped tires/wheels, putting the new non run-flats on the front, and the used run-flats on the rear. It drives like a completely different (normal?) car. No more of the squirrelyness (is that a word?) in the rear, or unneccessary DSC activation. I can tell that the turn-in is not nearly as crisp on the non run-flats, but it sure does ride better. I think I can live with this until I get new rear tires (non run-flats).

So while I certainly don't recommend mixing run-flats with non run-flats, if you have to do this, PLEASE make sure the non run-flats are on the front!

 

Sorry to hear about your experience.

You can try a little less air in your tires and stick to the smoothest lane if there is a choice, often the lane least used by heavy trucks.

There is nothing wrong with the Pilot Super Sports, you might have an alignment that is slightly off, suspension parts that are worn, or very bad roads which were less noticable with the worn runflats.

 

I'm a fan of weight reduction at the wheels. Getting lighter wheel/tires has got to give the best all-around performance improvement per dollar possible.

If you're reading this and you're ready to buy new tires, consider picking up a set of smaller/lighter rims.

I have a set of stock 15" holies on my R50 and I can lose performance just going with a wider, and therefore heavier, tire. I've tried a few sizes from the stock 175 width up to 205s and a small amount of weight can make a BIG difference in the handling and nimbleness of these cars.

I take tire shopping as an opportunity to try different configurations.

This can be done relatively on the cheap considering you can pick up a full set of stock wheels on this site for $100-$400.

Fun, ain't it?