abbeyrd

With all the neagtive feelings expressed on this site about the runflat tires, I was wondering why I haven't read complaints about those types of tires on other cars. I have never seen "Car & Driver" complain about runflat tires when on other cars. it seems BMW uses runflat tires now, yet C&D does not say
it's a lousy ride. They say in the current issue thatthe latest 3 series rides quite nicely on those tires. Maybe the SC430 in a suspension is just tuned lousy.
Any thoughts?

rclab1

Run-Flats on our cars ride just plain too stiff, compared with the other cars you mentioned, plus stiff, jarring ride on a close to 70K dollar car is sort of uncalled for, except in a true sports car.

da-bizket

BMW doesn't use run flat tires anymore. Wonder Why??

abbeyrd

Hey Da-bizket

read again. Car & Driver in the April 07 issue tested a BMW 328 that came with runflats.

LeslieRC

Yes they do still use them. My 645ci came equipped with run flat tyres. Surprisingly, the ride on them is much smoother than when I had them on my SC430s. I don't know if it's because of the difference between Dunlop and Bridgestone, that the 645 is a heavier car, or both. Anyway, my only complaint about the Bridgestones is that they are VERY expensive ($500/tyre).

da-bizket

I did a test drive on a new BMW 650 and it didn't have RFTs. The salesman said they were not using them anymore. Looks like he was talking a particular model. I confirmed this today with another salesman. The new 650 does not use RFTs. I apologize for the misunderstanding.

If my new tires and rims don't come in before I get my Tein CST installed I might be able to test your theory about the suspension. What about the road noise from the RFTs. I have Bridgestone Potenzas and they sound terrible. Anyone ever complain about that? I find it hard to believe the Lexus sound insulation is inferior to any other make of vehicle.

abbeyrd

Just went on the BMW site previewing the new 335 hardtop convertible.
It also comes with runflat tires. I'm convinced that it is the SC 430's suspension that is contributing to the subpar ride more so than the tires. As I said earlier, I have yet to read any reviews telling of rough ride quality of BMW's with runflats.

rominl

iTrader: (4)

honestly, you believe what you gotta believe, but a lot of people here change their runflats to normal tires with stock suspensions, and the ride improved a lot.

with that said, lexus did change the suspension in 05 i think

abbeyrd

I have an 06 and the ride is not that great. Don't get upset. I am just wondering why their cars have better rides on runflats. I'm sure C&D would complain if they rode like ours.

MBoom

I really don't understand the continuing angst over our run-flats. They do offer some genuine advantages in terms of safety, but the tradeoff is pretty clear--the sidewalls have to be stiff, to support the car in the event of loss of pressure. The SC's suspension settings, while not sports car-stiff, are somewhat stiffer than most luxury cars. The ride you get as a result is going to be less compliant than a softly sprung car or one with spongy tires. It's simply not realistic to expect anything different--simply put, there's nothing wrong with the tires. Yep, they're stiff, but they need to be to fulfill the function for which they're designed.

For those who truly need a softer, more compliant ride, the answer's pretty clear--buy the spare kit and switch to conventional tires.