At first look, run-flat tires seem like a great idea. No changing flats in the middle of the night and no spare tire, saving weight and space.
Yet sales are mostly in top-of-the-range sedans such as the Audi A8, BMW 7 series and the Rolls-Royce Phantom. The big exception is the BMW 1 series due in September.
But Peugeot is not following BMW's example. Bruno de Guibert, head of product planning, thinks the technology needs fine-tuning.
"It makes each wheel much heavier, perhaps 25 percent heavier than with a normal tire," he says. So there is little saving in weight. Moreover, a heavier wheel causes more vibrations, making the ride less comfortable, he says.