goodyear runonflat tyres

pressure drop

goodyear runonflat tyres

Goodyear's RunOnFlat tyre technology will change the way you think about tyres. Andy Enright reports

If, like me, you thought scary tyre deflations were things that happened to other people, you could be in for a rude surprise. Travelling along the A3 recently at almost legal speeds one evening, I felt the car I was driving shimmy, shake and then start to vibrate horribly. Training had taught me not to brake but not everyone will benefit from such training. By the time the car came to a halt, the tyre was so hot that it was impossible to touch and the heat had caused a partial delamination.

Not pretty at all and it necessitated twenty minutes sitting on the hard shoulder with articulated trucks hammering by inches from my posterior. Getting shot blasted with grit every thirty seconds or so isn't a great deal of fun, I can assure you of that. Things would have been a whole lot safer if I'd have had a tyre like Goodyear's Eagle NCT5-EMT RunOnFlat.

This is a tyre designed to run safely for a minimum of fifty miles at a maximum speed of fifty miles per hour with absolutely no air pressure required. When a Goodyear RunOnFlat tyre encounters a road hazard and loses air pressure, the vehicle remains supported by durable inserts in the sidewalls of the tyre, and it can continue to travel with minimal impact on handling. There is no loss of control or grip, which drivers experience with a flat in a regular tyre. RunOnFlat's reinforced sidewall inserts create greater stiffness and enable the tyre to bear the weight of the whole vehicle, even when the tyre is totally deflated. A major advantage of RunOnFlat tyres is that they can be fitted straight onto normal rims, with no need for special tools and extra costs.

The Goodyear RunOnFlat technology offers such high levels of safety that drivers may not even notice the sudden pressure loss. Special sensors monitor the tyre pressure in all four tyres and notify the driver of any loss of air pressure detected. Many of the latest car models on the market are equipped with this tyre pressure monitoring system. We decided not only to see whether Goodyear's claims were up to the mark but to wildly exceed them. We planned to fit a set of 245/40R18 RunOnFlat tyres to a BMW 530i, deflate all four of them and drive the Spa-Francorchamps race track as fast quickly as possible. What's more we'd keep lapping until the tyres became marginal.

We attracted some curious looks as we deflated the tyres fully and with the approval of the track safety team, we pulled out of the pit lane and accelerated down towards Eau Rouge. First impressions were promising. We'd done a lap with one flat front tyre and had noticed a slight pull to one side and an increase in noise. Goodyear's engineers claim they can reduce the steering pull and noise still further but wouldn't want to as some drivers would fail to notice they had a flat and would carry on obliviously.

With four flats, the car felt a little odd, as if the rims were trying to wrench themsleves free of the tyres. Teeth were gritted as we dropped into Eau Rouge, minds already furiosuly conjuring up excuses as to why the BMW would be returned to the press office with hideously damaged alloys. Despite the expectations of metal coming into contact with tarmac, it didn't happen. Must try harder. Through the Les Combes complex, the BMW leaned heavily on the reinforced sidewalls but again kept resolutely on line. Even the Rivage hairpin, a punishing test for cars with correctly inflated tyres, was tackled easily, albeit with plenty of speed scrubbed off in the process.

Even the scary corners of Pouhon and Blanchimont were tackled with a fair degree of confidence, accelerating out of Blanchimont, we briefly saw 110mph on the speedometer and still the big BMW felt composed. It felt a little squirelly into the angled braking zone of the bus stop chicane but this was only to be expected. We went round for another lap, then another and before too long we were starting to overtake other cars. After nine laps - that's nearly 39 miles at maximum attack - we pulled back into the paddock not because the tyres were tired but because the brakes were starting to wave the white flag!

Naturally, we wouldn't recommend trying to replicate this test on the open road, but as a demonstration of the safety margins built into these impressive tyres, it's an exercise worth undertaking. More and more people seem to agree, the advantages of run-flat tyres being easy to appreciate. Aside from the issue of not having to change tyres by the side of a busy motorway or in an unsavoury part of town, it also means that cars like today's MINI, which can feature wheels up to 18 inches in diameter, are now relieved of the problem of where to fit the spare. Less weight, more luggage space and greater safety are other obvious side effects. Sales of run-flat tyres have risen more than tenfold over the past four years. It seems as if it really is time to shed our spare tyres at last.