- The Washington Times - Friday, November 17, 2000

Michelin has come up with a new tire design that purportedly makes it impossible for a deflated tire to come off the rim, a common cause of loss of control.
Traditionally, air pressure forces what is called the "bead" or edge of the tire against the lip of the wheel. When tire pressure is reduced or eliminated, the bead no longer is pressed against the tire and can work its way away from the wheel rim into the middle of the wheel. Once this happens, a driver effectively loses control of the car.
Michelin's new Pax System uses the dynamic forces of the vehicle's weight and the tire design to lock it against the wheel, eliminating any dependence on air pressure, a company spokesman says. You won't lose control with a flat.
As if this weren't enough, gas mileage is better with Pax tires by as much as 10 percent, reports indicate. The tires also generate less road noise, developers say.
There's more. A Pax tire will act as a "run-flat" tire if punctured, so long as you don't exceed 55 mph and don't travel more than 125 miles on your flat tire. At zero pressure, the tire rests against an interior support ring that keeps it from collapsing on the wheel.
Car manufacturers are reportedly delighted with the design, since new cars (the 2003 Cadillac Roadster will be the first) can be made without space for a spare.
Michelin will produce the tires with imbedded pressure sensors in each. That's the only way to know when one goes flat. The sensors communicate with a dashboard display and warn you when there is a problem. On average, people travel 28 miles to get a flat fixed (according to Michelin research), so the 125-mile range on the flat Pax tires gives plenty of extra mileage, even if you are caught far out in the hinterlands.
This technology may revolutionize not just tires but a lot of the automotive industry. As mentioned above, it will allow designers to eliminate the space required for spares. That could mean additional storage space, bigger fuel tanks and lighter vehicles. Wheels will also need to be designed to fit the new tires.
Pax tires are the first to offer a low profile (sit low to the ground) for heavier vehicles such as minivans and sport utility vehicles. How this will affect design is anyone's guess, but it probably will.
If you're looking for a downside, it might be that since Pax tires do not have the bead area of the traditional tire, they can't be installed in the same way. Tire installers will need new equipment to work the tires on and off your car, and you won't be changing a flat out on the highway. You'll have to drive to the nearest installer and read old magazines on a gritty couch until your tire is fixed. (Pax tires can be patched from the inside, just like today's radial tires.)
Pax will not remain solely a Michelin technology. Already the company is working with Pirelli and Goodyear to make the tires.

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