Thoughts on Run Flats

Run flats would probably never enter my vocabulary as they are tires for other people, so I thought. That is until the '09 335xi came w/ a low mileage set of 225/45R17 Michelin Primacy MXM4 ZPs on the BMW factory wheels.

As every tire is a compromise of some sort I thought I'd hate them. They soak up the road good enough although a little firmer than any other DD tire I'd normally run. Bridge expansion joints still ka-lunk but so did the others over the last 30 years on this same commute. 18's may be another story for sure. Although the xi is not an AWD snow car per se these tires aren't bad in light snow, 4X4 truck w/ A/T's for heavier snow FTW. The E92 chassis height would further rule out heavy snow as well.

As I tried to find something wrong w/ these tires I really have no complaints. Obviously they are not an auto-x or HPDE tire (again, always a compromise) they do what I need them to do in DD service. One plus is the run flat feature that would save my butt on my almost 40 mile one way commute. Although I have AAA and not fond of changing tires at night anymore that works for me. Also, Ze Germans in their ultimate wisdom decided this is how it will be. I'll be shopping aftermarket 18" wheels and performance tires in the spring for summer duty as the E92 is a keeper now.

After these Michelin run flats are run out though I may look at another set... or maybe winter tires on the stock rims.

While I don't necessarily expect GRM to embrace them, what are your thoughts and experiences on run flats?

I got 'em off my MINI ASAP. Harsh ride, expensive to replace. I carried a repair kit and a tiny compressor. Ironically, I had three flats with that car, three more than I've had with any other car. The repair kit and compressor worked fine in all three cases.

Basil Exposition wrote: I got 'em off my MINI ASAP. Harsh ride, expensive to replace. I carried a repair kit and a tiny compressor. Ironically, I had three flats with that car, three more than I've had with any other car. The repair kit and compressor worked fine in all three cases.

Mine were brutal. And monstrously expensive. Lolnope.

I have the factory model ones on my '06 MX5 commuter. Other than the tire guys REALLY not liking the work to install them, they are sticky, quiet, and have worked well for me.

I do run seperate winter tires though. Blizzaks beat all seasons all. day. long.

Noisey, harsh ride, heavy, impossible to estimate tire pressure visually, expensive.

I will not replace them with the same on the Mini.

My understanding is that once you have run them flat, they need to be replaced. The stiff sidewalls will let you roll to a tire shop, but that doing so without air pressure damages the tire where the sidewall joins the tread.

bentwrench wrote: Noisey, harsh ride, heavy, impossible to estimate tire pressure visually, expensive. I will not replace them with the same on the Mini.

Forgot that they last half as long as standard tires as well...

Dang, not much love at all for RFT's across the forums. The Michelin ZP's still aren't offensive to me (paid for too) but a summer performance tire is the obvious answer for the E92 sport suspension. Looks like running out the ZP's then Eagle F-1's or similar on 18" VFR V703s or Beyeren Mesh wheels in the spring. Tire Rack has a Continental 12V compressor/ sealant kit that's reasonable. Factory wheels will get Blizzaks. Sounds like a plan.

Up to speed now.

Thanks all

Somehow I suspect run flat tires were a German idea.

I know some people who run snow versions in stock rallyx classes to some success. It's a good, if not cheap, answer to usually squishy snow sidewalls.

fasted58 wrote: Dang, not much love at all for RFT's across the forums. The Michelin ZP's still aren't offensive to me (paid for too) but a summer performance tire is the obvious answer for the E92 sport suspension. Looks like running out the ZP's then Eagle F-1's or similar on 18" VFR V703s or Beyeren Mesh wheels in the spring. Tire Rack has a Continental 12V compressor/ sealant kit that's reasonable. Factory wheels will get Blizzaks. Sounds like a plan. Up to speed now. Thanks all Somehow I suspect run flat tires were a German idea.

Don't know if they were a German idea, but I think the first production car that had 'em was the Corvette. We had a C5 and they were stupidly expensive to replace with the OEM brand, which I think was Goodyear. We got some Michelins, instead, but they didn't wear evenly and had to be replaced quickly.

My wife's daily has Pirelli Cinturatos. They drive fine and are not noisy at all. The first set lasted 25k miles. The car is all wheel drive.

"I wouldn't use a run-flat for a backyard swing."

Mike Miller.

Everyone I know that had RFTs ran them on the car till they wore out then replaced them with regular tires. Mainly for cost, run flats are $$.