PARIS -- Michelin anticipates sales of run-flat tires to increase significantly as car manufacturers start to install them on higher volume cars.
Run-flat tires have been confined mostly to premium or luxury models, such as Audi's A6 and A8 and the Rolls-Royce Phantom, although BMW's Mini Cooper also has them.
But BMW's decision to make them standard on its new 1 series is a breakthrough in volume, says Michelin, which is one of the tire suppliers for the new model.
Nissan and Honda plan to use Michelin's PAX run-flat tires, but they have not specified the models.
"Run-flat tires sales are finally taking off," said Michelin spokeswoman Fabienne de Brebisson.
Michelin expects global PAX tire sales to grow to between 200,000 and 250,000 four-tire units a year in 2005.
In 2000, Michelin, Goodyear and Pirelli agreed to exchange run-flat technology and offer automakers multisupplier deals to reduce their business risk. Bridgestone also manufactures run-flat systems.
Run-flat tires allow a motorist to drive a car with a punctured tire up to 125 miles at a maximum speed of 50 mph before repairing the tire.
Bridgestone is the main supplier of run-flat tires for the BMW 1 series, but Michelin also supplies BMW with its zero-pressure tires for the model. The 1 series goes on sale in Europe in September. BMW can build 150,000 a year.
Michelin's PAX system consists essentially of a rubber ring around the rim of the wheel inside the body of the tire. If the tire loses air pressure, the rubber ring supports the tire tread so the car can continue to operate at lower speeds. Michelin's ZP family of tires has reinforced sides to withstand the increased flexing that comes with running while deflated.
BMW has been the industry leader in adopting run-flat technology. It first used it on the limited-edition Z8 premium roadster, which went on sale in the United States in 2000 and was discontinued last year.
A car with run-flat tires can be designed with more trunk capacity because the spare wheel, jack and tools are eliminated. But the weight saved is reduced because run-flats weigh more than standard tires.
Initially, four PAX tires weighed the same as five standard tires. But four PAX tires now weigh the same as 4.7 regular tires.
"We keep working on that weight issue," said a Michelin spokesman.
But French automakers say PAX tires require a stronger chassis and suspension, which adds to manufacturing costs.
Also, tires represent so-called unsprung weight - mass that reacts directly with road irregularities without being softened by the suspension - so PAX tires make it more difficult to provide a smooth ride.
Renault sold a few thousand first-generation Scenics with the PAX system but doesn't intend to do so with the new Scenic. Said a Renault spokesman: "The value for the money isn't there."