gavriil

BMW pushes run-flat tires despite higher cost, cites safety - - By JENS MEINERS | Automotive News Europe - - Source: Autoweek

MUNICH -- BMW will make run-flat tires standard on its upcoming 1 Series entry-premium car.

This will be the highest-volume car yet equipped with run-flat tires as standard equipment. BMW has been the industry leader in adopting run-flat technology, first using it on the discontinued limited-edition Z8 premium roadster.

Run-flat tires are standard on the BMW 6 Series and the Z4. They are also mounted on optional 5-series wheels, which are on more than 60 percent of the 5 Series models sold. Most versions of the Mini also have them.

Run-flat tires cost up to 20 percent more than regular tires and weigh more. The wheel-and-tire system allows motorists to continue driving on a punctured tire for a significant distance, although at lower speeds.

"We are increasing the use of run-flat tires because of the added safety," said BMW spokesman Alfred Broede. "Drivers can easily handle a tire blowout even at high speeds."

Using the systems for all versions of the 1 Series has let BMW create space to put the battery in the rear.

"This is an advantage for weight distribution," Broede said.

Tire manufacturers hope the 1 Series becomes a breakthrough for run-flat tire technology.

There are two competing run-flat systems: The Michelin-invented PAX system and the less expensive and more popular SST system made by various suppliers. BMW and Mini use the SST system.

charliemike

Entry-Premium? ROFL!

Hey Ultimate Driving machine Corp? I have a question ... What about all that extra unsprung weight those runflats add?

lolkthxbi

gavriil

I was thinking about unsprung weight. It's mentioned in the article that they are heavier than normal tires.

Here's what's happening inside every responsible auto manufacturer. There is the performance engineers and then there is the folks that care about safety (there are other groups too). They all have different priorities, which many times overlap with each other's priorities. So there is this constant "war" of what should be added to the design of the car and by how much. In this case, the safety group won, with the addition of RFTs. It's all about compromises.

charliemike

Unless these tires prevent blowouts, there is no real compelling reason (in my very humble opinion) to go with run-flats.

If they don't help with blowouts, then it's a matter of convenience not to have to change a flat. I dunno, I'm not sure that it's as cut-and-dry as BMW states.

heyitsme

Luckily I've never gotten a flat on the highway but seeing people that have-it looks to be a terrible experience, especially if you're on your way to work, etc. Be nice to be able to drive to work and change it there instead of on I-95 or waiting an hour for someone to come change it for you.

gavriil

RFT's main advantage is that, in a case of a blowout, they almost eliminate the chance of you losing control of the car. That's the main benefit.