Michelin admit run-flats are flawed.

[Snake Vargas]

Yeah, I want normal tyres as well. As with any newish technology, I expect them to improve to some extent, but the issue isn't if they will improve or not, the issue is that I don't want to be a guinea pig.

I'm glad BMW went out on a limb to promote what they think is the way of the future. I just don't want to have to put up with it in the mean time.

[BMW_Dude]

I know runflats aren't great, but as shown by the new 3er, if the suspension is tweaked to work with run flats, the ride can be very good!

It's just a question of time before all cars use these tires!

[Snake Vargas]

Well, I'm not sure if it's because the journalists have been prejudiced knowing that the 3er has runflats, but nowhere has it been praised for its exceptionally smooth ride. Sure, it's a BMW and not a Merc or Lexus, but they say that even the E46 had a more compliant ride and the same sportiness. Adding sports suspension to some reviewers' cars has only exagerrated the problem all the more.

If they're the future, I still say I'll wait until they get a lot better.

[bmwrules]

Originally Posted by BMW_Dude

I know runflats aren't great, but as shown by the new 3er, if the suspension is tweaked to work with run flats, the ride can be very good!

It's just a question of time before all cars use these tires!

I wouldn't necessarily use the 3er as an example of a smooth riding car with run flats. Both of my BMWs are run flat equipped and both have the sport package. But the 545 has the smoother ride over the 330. My wife who drives the 330 every day makes that comment almost everytime we ride in my 545 together.

While run flats are relatively new, the have been around for 12 years. In 1994 the C4 Corvette was the first production car to offer run flats as an option.

http://autos.msn.com/advice/article....tentid=4021164

The first "run-flat" tire available on a regular production vehicle was offered as an option on the 1994 Chevrolet Corvette. Goodyear's EMT tires then came standard with the fifth generation Corvette, introduced as a 1997 model, an industry first. This design uses reinforced sidewalls that enable the tire to support its share of vehicle weight without collapsing measurably. The tires can be mounted on standard wheels.

Then, in 1996, radial tire pioneer Michelin unveiled a different principle that centered on a solid inner wheel "insert" on which a pressure-less tire could run safely for some distance. A year later, the French manufacturer revealed its Pneu ? accrochage vertical or PAV, which can be translated as "Vertical Anchorage Tire" for the way the tire bead "seats onto the rim vertically." The new concept made run-flat capability possible without having to contend with a large performance compromise.

[BMW_Dude]

Oh right bmwrules, the reason I said that was because I heard somewhere that the 3er suspension was tuned to work with run flats, and that wasn't the case with the 5er! Obviously I'm wrong!

[bmwrules]

Originally Posted by BMW_Dude

Oh right bmwrules, the reason I said that was because I heard somewhere that the 3er suspension was tuned to work with run flats, and that wasn't the case with the 5er! Obviously I'm wrong!

I wasn't trying to bust your chops, I was just stating what my personal experience with both cars was. No need to get huffy.

[SteveLee]

Originally Posted by bmwrules

While run flats are relatively new, the have been around for 12 years. In 1994 the C4 Corvette was the first production car to offer run flats as an option.

Run-Flat Tires:A New Standard Rising - MSN Autos

I think you'll find he first car to have run-flats offered as options were various British Leyland cars in the mid 1970s, they were options on the Mini 1275GT in 1974 - 20 years before the C4. These became standard on the Mini Clubman in 1977. Dunlop Denovos (the first "run flat" pneumatic tyres) were co-developed by British Leyland and Dunlop. I believe they were also available on Rover SD1s and later the Princess.