With the winter tire market starting to develop in the UK, a lot of people have been discussing all season tires. UK winters are characterised by long, cold wet spells, and when the snow falls our road systems grind to a halt due to 99% of the cars in use are running summer tires.



For those people who don't want the hassle of changing their tires twice a year, all season tires seem like a logical compromise. Designed to work year round, in theory the all season tire can offer 90% of the wet and dry performance of a summer tire, combined with 90% of the performance of a winter tire on the snow. If these tires are able to offer that sort of performance, with similar year round qualities of a summer tire, what are the draw backs?

Is there such thing as an all season tire

The definition of a modern all season tire is subject to a lot of debate in the tire industry.

All tires are a compromise of performances, and modern all season tires, such as the Goodyear Vector 4Seasons, Vredestein Quatrac 3, Hankook Optimo 4S and Kleber Quadraxer could easily be defined as "wet optimised" winter tires.

These modern all season tires are patterned and siped like winter tires, but use slightly less winter optimal compounds to improve wear and dry weather ability. Certain tires from the Nordic companies are actually called winter tires in the UK, but the same tire is referenced as all season tires in other climates.

So how do they actually perform?

To help us benchmark all season tire performance, we've turned to the Auto Bild 2012 Winter tire test. In that test, 15 winter tires were tested, and they included a summer tire, and the Goodyear Vector 4Seasons all season tire.

For the purposes of consistency we will reference the Goodyear all season tire, against the test winning Continental Winter Contact TS850, and the summer tire.

It's no surprise the summer tire doesn't perform on snow, nor is it a surprise that the all season tire can't quite match the winter tire in the same snowy conditions. What does get interesting is when we look at the wet, dry, wear and rolling resistance scores of each tire.

Under dry braking the results are extremely close, with the winter and all season tire stopping just 0.3 meters apart in favour of the all season. Change the surface to wet, and we find that the Continental winter tire actually stops just 2 meters behind the summer tire, while the all season tire takes a further 5.2 meters to stop.

It's a similar picture during the handling tests. The summer tire couldn't even manage a lap on snow, while the all season tire got within 3.5 kph of the winter. In both the wet and dry the summer leads by a margin, but in both these tests it's the winter that out performs the all season tire. Not what we'd necessarily expect.

The Goodyear has a slightly higher projected mileage, at 38550 kms compared to 33700 for the winter (the summer tire wasn't tested), and during the rolling resistance tests it was actually the Continental winter tire which had the lowest rolling resistance, so would use the least fuel.

To conclude

What can we conclude from this test? The evidence suggests that the technology to create a true all season tire doesn't yet exist, and looking at the balance of qualities, the best winter tire on sale in the UK is actually a better year round tire than the leading all season contender. The Continental works better in the snow, better in the wet during handling, braking and aquaplaning tests, and in the dry it's only narrowly beaten under dry braking, but wins again during the dry handling tests. We’re waiting for the confirmation of the wet and dry test temperatures, but we believe them to be around 7c.

All tires are a compromise, and a siped tire with a compound designed to work in a large range of conditions is more of a compromise than most. Unfortunately, a true all season tire still doesn't exist, and for optimum year round grip we need to run two sets of tires. As a summer tire offers little to no performance in the snow, an all season, or good quality winter tire can be a sensible year round compromise if you don't want the bother of running two sets of wheels, but want to be mobile regardless of the conditions.

The Continental Winter Contact TS850 has moved the game on for winter tires, and based on these test results, would anyone question if it was labelled an all season tire?