Winter tyres & tyre labeling

by chris sanders on 10th October 2013

Winter Tyres & Labeling

tyre_labelRecently I have been involved in a number of motoring forums and after reading various threads about winter tyres and the new labelling system I have been drawn to write this post. I have seen a number of comments about tyre labelling and particularly the poor wet braking results that winter tyres tend to show. For those not heavily involved with winter tyres these label results can be really confusing, it’s not uncommon to see great quality winter tyres with wet braking results of E & F. Yet the tyre manufacturers and winter tyre retailers often try to promote the term ‘cold weather tyres’ and claim these products offer shorter braking distances in a range of winter conditions, not just snow & ice.

So how can a winter tyre with a wet braking result of F, offer shorter braking distances in the wet? Well to be quite frank it’s because the tyre labelling system is a complete joke!

wet_grip_tyre_labelThe testing process that tyres have to go through for their tyre labelling values is standardised, and with good reason. In order to have consistent results across brands this needs to be the case. However the testing across different types of tyre is also standardised, so summer tyres, all-season and winter tyres are all tested in the same way. This standardisation states that all tests should be carried out at 25 degrees Celsius! So a cold weather tyre that is designed to offer superior performance in colder conditions has to be tested in a temperature range outside of what it has been designed to perform at. The rubber polymers that make up a winter tyre are designed to ‘work’ (be that stay supple in the cold to offer short braking distances, superior grip…) at temperatures below 7 degrees, therefore the labelling results from a test at 25 degrees don’t say anything at all about their actual cold weather credentials.

Winter tyre manufacturers will happily admit that their products won’t perform quite as well as their summer counterparts in warmer conditions, because this is not what they are designed to do. If the tyre manufacturers were allowed to test their winter tyres in more suitable conditions (less than 7 degrees) then the results would be very different indeed. Tyre labels were designed to offer the consumer more information on the products they are looking to buy but for winter tyres they just increase confusion, well done the EU! To be honest I have issues with tyre labelling even for summer tyres, if you’re interested you can see my rant here.

It’s not just the wet braking result that I have an issue with though, lets take a look at the other criteria.

fuel_tyre_labelFuel efficiency – this test looks at a tyres rolling resistance and aims to show how products compare in terms of how fuel efficient they are. Well winter tyres have 2 things that will not go in their favour, firstly they have sipes. Sipes are the little zig zag lines that run all over the tread blocks, these offer additional biting edges that allow the tyre to grip in snow, ice and slush. All winter tyres have these and they are incredibly important when it comes to winter traction. Also winter tyres have more aggressive tread designs; often they are directional and have unusually positioned tread blocks. Such designs again add to winter performance, yet both of these design features are not going to improve fuel efficiency. Hopefully you are considering winter tyres because you want to drive safely in the colder weather, well with tyres if you want to excel in certain criteria then there is always a compromise. In this case the compromise is partly on fuel efficiency. Finally it’s worth mentioning that the difference between the best and worst performing tyres within the tyre labelling results equates to a full tank of fuel over the whole life of the tyre, in terms of the actual affect to mpg the difference is relatively minimal.

noise_tyre_labelOne of the other factors that have to suffer in order to perform in the snow is the final part of the tyre labelling criteria; noise. The very same features detailed above (siping & tread block design) will also generate a bit more noise than a summer tyre. You will have seen that most modern summer tyres have that very standard design with around 5 circumferential grooves, well this is the type of design that will be nice and quiet. Winter tyres are designed differently and unfortunately one of the by-products of this is (slightly) increased road noise.

It’s frustrating that winter tyres have to be rated in the same way as a summer tyre as none of the things that they are designed to do can be seen from the tyre label. What would be useful for consumer to know is stuff like; how quickly the stop on snow, how quickly they stop in the wet in colder conditions, ability to grip on ice….. If this is not to be the case then surely it would be better to not make winter tyres have to display any data at all?

My worry is that a motorist is considering winter tyres for the first time and is then put off as they are led to believe that the product will not perform well in the wet. As we are well aware British winter can bring a lot of rain and in fact a winter tyre will offer increased safety when it’s wet and cold, it’s just not possible to get this message over with the current tyre labels.

As a retailer through our company Tyremen we legally have to display the label data to visitors to our store and website. It’s just a shame that we then have to spend the time in educating the public to disregard this information all together. Maybe I could be bold and take the data down for all winter tyres? In the mean time I hope this post helps to show that all is not as it appears when it comes to winter tyres and tyre labeling.

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{ 2 comments… read them below or add one }

Mark Wilcox November 8, 2013 at 7:29 am

Good post. Maybe there should be two sets of data displayed, one at 25 degrees Celsius and one at the magical 7 degrees Celsius. This would allow Summer, Winter and All-Season tyres to compete with each other fairly and show the advantages / disadvantages of each at different times of the year.

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Phil February 15, 2014 at 5:28 pm

In a mild wet winter such as the one we are currently experiencing here on the South Coast of England, I think the standardised wet braking testing for both winter and summer tyres provides a useful comparison when selecting a winter tyre.

Since late October 2013 to now (mid-Feb 2014) I’ve been running on Continental WinterContact tyres, and consciously been monitoring my dash-board thermometer when in the car. During my typical commuter time driving, the dash temperature has typically hovered above 7 degrees C, and often been well over this figure. The roads have been wet (as an understatement). Operating outside of their intended temperature of below 7 degrees C, it is a helpful comparison to know my Continental Winter Tyres offer C-rated wet braking, as a C-rated summer tyre would in these conditions. Had I chosen a winter tyre with a lower wet-braking test letter, this would not have been the case, however well it performs sub-7 degrees.

These 2 test videos illustrate this point well, both above and below 7 degrees C.

At +10 degrees C in the wet, the ‘B’ rated Michelin Alpin Winter tyres took 7 meters more than Michelin Primacy HP Summer tyres (also ‘B’ rated) in an emergency stop from 70mph.

Source AutoCar’s test:

http://www.autocar.co.uk/car-video/winter-tyres-tested-wet

So, in a mild wet winter such as the one just experienced in the South of England, switching to winter tyres could in fact be increasing wet breaking distances by almost as much as not switching to winter tyres in the cold winter of the previous year when drive-time temperatures were consistently below the 7 degree C tipping point.

At +6 degrees C in the wet, Continental Winter tyres stopped 7m shorter than Continental Summer tyres in an emergency stop from 50mph (N.B. 50mph not 70mph as in the AutoCar test)

Source Auto Express’ test (supervised by the RAC):

http://m.youtube.com/watch?v=elP_34ltdWI&desktop_uri=%2Fwatch%3Fv%3DelP_34ltdWI&gl=GB

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