Who makes Goodyear self-sealing tires

Seal tires - it's all about the filling

Anyone who has already experienced it knows what a flat tire means: the car is parked - with a lot of luck at least in a safe place - and nothing works anymore. Even with a spare or spare wheel on board, a lot can still go wrong: Windy jacks and bad tools, paired with mercilessly stuck wheel bolts, make even people without two left hands despair.

Since manufacturers have switched to putting only one breakdown assistance set in the trunk ex works, maintaining mobility on your own has not exactly become any easier. Anyway, a repair attempt is crowned with success in the rarest of cases. Sometimes the pressure of the compressors is not sufficient, sometimes the sealant goes completely different ways than intended. Not to mention the continuing danger of tinkering on the side of the road.

But there is a solution: Various manufacturers such as Continental, Pirelli, Hankook, Goodyear and Michelin have developed tires that can repair themselves at least if the tread area is punctured. In contrast to tires with run-flat properties, which thanks to the reinforced sidewall only allow driving to the next workshop at 80 km / h, these self-sealing tires can theoretically continue to be used without restrictions. The VW Passat and the new VW Aerton are even delivered from the factory with such tires. But these miracle tires also fit on normal rims and can also be retrofitted. The price is ten to 20 percent higher than that of conventional tires without this technology. Almost too good to be true.

Sticky mass seals tires

The principle of self-healing, called seal technology by the manufacturers, is surprisingly simple: a dimensionally stable, sticky mass is applied to the inside of the tire. If a foreign body sticks through the tire, the mass will surround the intruder. If this is pulled out, the air pressure inside the tire ensures that the compound is pressed into the hole and seals the opening. According to the manufacturer, this works reliably with holes up to five millimeters in size.

In cooperation with GTÜ (Society for Technical Monitoring) and the Austrian partner club ARBÖ, ACE LENKRAD has tested whether this is actually the case using the three tire types Hankook Ventus Prime2 Sealguard, Continental SportContact 5 with ContiSeal and Pirelli Cinturato P7 Seal Inside. For this purpose, a VW Passat was equipped with these 235/45 R18 94W tires and the tires were punctured. Of course only in the area where the compound is applied.

If the side wall is damaged, for example on a sharp curb, this system is ineffective. The sensitive side walls are cut out, otherwise the tire would lose its own damping. The ride would be very uncomfortable and the tire would be very heavy.

The self-sealing tires already weigh 1.4 to 2.2 kilograms more than their conventional brothers and sisters. Sensitive drivers can even feel it. The rotating, unsprung masses are larger, but the rolling noise is more subdued. In general, however, no loss of driving characteristics or grip is to be expected. Even a braking test on a wet road did not reveal any further disadvantages.

The most important thing, however, is that screws or nails actually lose their horror in this way, as the experiments by ACE LENKRAD show. The choice of means was anything but squeamish: With the help of a device, the right front wheel was perforated three times in three different places with a four millimeter thick nail. At the same time, three four millimeter thick wood screws from the hardware store were screwed through the carcass of the left front tire and left in the tire. And indeed: Neither with one nor the other method does air escape from the tire. Not even in the short term at the moment of damage.

Test drive confirmed - tires remain tight

Immediately afterwards, the maltreated tires were subjected to an extensive test drive with high loads on the test track. Even then, the otherwise very sensitive, active tire pressure control system of the VW Passat did not sound an alarm. The air pressure remained constant. And there was no loss of air on the following day either.

The tires were then carefully examined. On closer inspection, tiny black dots give an idea of ​​the places where the nails have penetrated. The other tire looks more spectacular: The screws have been pressed in under the weight of the car, the screw heads are correspondingly damaged by the brisk drive. However, all manufacturers recommend removing the foreign bodies so that the holes are not unnecessarily widened by the movements of the foreign bodies.

Lo and behold: no air escapes even when the screws are unscrewed. However, until now, the clicking of the screws on the asphalt was the only way to even tell that something was wrong. Unless you happened to see the foreign body stuck in the tire.

No loss of air, no warning message, no restriction in driving behavior. The consumer could easily succumb to the temptation to simply continue using the tire up to its wear limit. Behind the scenes you can hear that this would be technically possible. But it is basically not allowed. Officially, such a tire is considered damaged, which in fact it is. Eventually an object penetrated the carcass and possibly caused damage there too.

Damaged tires should be checked

However, a damaged tire must be examined by a specialist as soon as possible. Paragraph 36 of the Road Traffic Licensing Regulations is clear in this regard. There you can read accordingly: A tire can be repaired, but the tire repair is only permitted after dismantling, thorough examination and carried out by a specialist. The legislature can still do little with the new technology. According to the Bundesverband Reifenhandel und Vulkaniseur-Handwerk, even the introduction of preventive sealants is not permitted - at least in liquid form. In any case, a seal tire must not be advertised as self-healing or puncture-proof.

The additional cost of materials and the recyclability of Seal tires are certainly an (environmental) issue. But banning this type of tire altogether would mean consciously exposing the driver to all the risks of a flat tire and the associated dangers. And nobody can want that.

Watch our film about the tire test - Special Seal tires (4:16 min.)

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