Tyres aren't very interesting for most people – and yet doing some research before you buy could save your life.
It’s not just about buying from well-known tyre brands, either. Different tyres perform differently across different conditions. Currently, the technology doesn't exist to create a perfect tyre in all conditions, so manufacturers have to balance opposing performance categories such as dry grip, wet grip, hot temperature performance, cold temperature performance, aquaplaning ability, wear and noise.
With such opposing performance requirements, a tyre that works at its optimum in the hot, dry conditions of a British summer will often struggle in the depths of a freezing winter. Meanwhile, a tyre which is most at home on snow and ice will be far from the optimum choice when the weather warms up.
Summer vs winter tyres
Tyre manufacturers claim that 'summer' tyres – which are used by 95% of UK motorists all year round – are the optimal choice for approximately 65% of our driving year, and that for the other 35% of the time, so-called 'winter tyres' would be better. They are claimed to marginally improve performance at temperatures below 7 degrees celcius, but in reality it's in freezing, snowy and icy conditions that you'll really notice a benefit over summer tyres.
For most people, however, the prospect of buying, fitting and storing a set of summer and winter tyres is too much to contemplate, especially when there’s no certainty of freezing, snowy or icy conditions in the UK.
In the video below, you can see just how much more traction winter tyres have compared with summers in extreme conditions.
In response, the tyre industry has developed 'all-season' tyres. However, until recently these were a compromise, with manufacturers taking winter tyres and then modifying them so the balance of performance moved slightly away from snow and ice, and towards wet and dry running. As a result, while the tyres had a broader range of ability, they also had some of the warm weather shortcomings that winter tyres suffer with, such as compromised dry braking.
Then, in 2015, Michelin released the first all-season tyre to start its life as a summer, not winter, tyre – the Michelin CrossClimate. The CrossClimate is claimed to have the performance of a summer tyre in warm conditions, plus 95% of a winter tyres performance during traction and braking tests on snow and ice.
Which are the best tyres? Our test process
In order to judge which tyre type is optimum for use in the UK, we took each of the leading tyres in their respective categories and put them through objective dry and wet braking and handling tests, as well as snow traction and braking testing.
The wet and dry tests were undertaken at the industry standard testing facility MIRA, in typical UK summer conditions. The air temperature was in the high teens, and thanks to cloud cover the track temperature was barely any warmer. For each of the braking tests the runs were repeated at least five times per set of tyres, with any erroneous times removed before an average of the results was taken.
For wet and dry handling we timed a number of consistent laps and averaged the best, but ensured our time variance was all within a second of the best time set by that tyre.
The snow tests took place on real snow, at Tamworth Snowdome. Instead of repeating the timed measurements from the wet and dry testing, we chose to simply try and get the vehicle up the ski slope, and to see if we could stop the car safely on the way back down.
All tests were performed on a Skoda Octavia wearing the most popular tyre size in the UK, 205/55 R16.
The tyres we tested
Michelin's Primacy 3 Represents the summer tyre category, as a result of winning the rigorous European standard ADAC tyre test in 2015. In that test it was commended for an excellent all-round balance of performance, and also having the lowest wear in test.
Goodyear's Vector 4Season Gen-2 A traditional all-season tyre, and a successor to the popular first generation version of the same name.
Michelin CrossClimate Evolved from a summer tyre and represents the latest approach to year-round motoring.
Continental's WinterContact TS850 Having won more than 23 winter tyre tests since launch, this is widely regarded as the standard setter in thd field.
How the tyres performed
Tyre performance in the snow
In the snow, the four tyres performed exactly as you would expect. Our traction and braking tests mimicked the struggle of climbing a steep snow covered hill, which so often causes traffic chaos during extreme weather.
The summer tyre couldn’t find traction as soon as all four wheels hit the incline, with the vehicle's momentum quickly running out, leaving the car wheel-spinning to a permanent stop. The winter, all-season and CrossClimate tyres all made it up the slope, with the winter tyre having a small advantage during the early traction phase.
Braking on a snowy decline led to similar results. The summer tyre failed before it started, because even using a tow vehicle we were unable to get the summer tyre far enough up the incline to perform a braking test on the way down.
The winter, all-season and CrossClimate tyres all stopped the car in a controlled manner, again with a small advantage to the winter and all-season tyres.
Tyre performance in the wet
Due to how sipes – the small cuts in the tread pattern of all-season and winter tyres which are designed to cut through water and snow - deform under emergency braking, tyres with this pattern will always struggle in braking tests outside of snow and ice.
During wet braking, the summer tyre had the clear advantage, taking just 33.97 meters to decelerate the Skoda from 50 to 5mph. The Michelin and the Continental winter tyre were closely matched at 34.74m and 34.82m respectively. And the Goodyear all-season tyre performed worst, taking an average of 35.54m to stop the car.
During the wet lap time tests, the results were slightly more surprising. The Continental winter tyre posted the fastest wet lap, averaging 54.4 seconds. The CrossClimate again placed second, averaging 55.3sec, with the Goodyear ‘all-season’ a close third, at 55.69sec.
The summer tyre, surprisingly, finished in last place at 56.67 seconds, due to struggling with standing water more than it's heavily treaded rivals, and a less predictable balance.
Tyre performance in the dry
As in the wet, the summer tyre had a braking advantage, but this time the advantage was even more pronounced.
The summer tyre stopped the car in 36.2m, and the CrossClimate 2% behind in 38.88m. The third-placed Goodyear all-season tyre took another five metres, or 15% further, to stop, totalling 41.65m. The winter tyre took nearly 20% further at 44.92m.
Dry handling again highlighted the disadvantage heavy siping has in dry weather performance. The summer tyre was the fastest round the track, completing the lap in an average of 43.33sec. The lightly-siped CrossClimate was a close second, averaging 43.37sec per lap, the winter 44.87secs and the all-season tyre 44.93sec.
Is there a perfect tyre for year round use?
As you'd expect, the summer tyre is the best choice when it's dry and warm. But while it didn't give up too much grip in the wet tests, it's total failure in the snow proves it isn't suited to the worst weather that we can get in the UK.
The winter and traditional all-season tyres, by contrast, excelled on snow but struggled in the dry. With up to a 20% dry braking penalty over an equivalent summer tyre, they're definitely not suitable for year-round motoring.
Instead, it's the Michelin CrossClimate that is the best all-rounder. It had none of the heavily siped tyres’ disadvantages in the dry, equalled the best in test during the wet testing, and clearly has enough snow traction ability to get you safely moving and stopped on snow covered hills.
Of course, it is worth stressing that for more extreme climates, where snow and ice are a more regular occurrence, the CrossClimates’ snow-handling penalty would be more apparent.
So can you use one tyre for year round motoring whatever the conditions? Well, in most parts of the UK the CrossClimate should meet all your needs, but if you live in remote regions of Scotland or plan on driving into an area such as The Alps, a summer and winter pairing of tyre sets is still the safest way of staying mobile.
It should also be noted, that the CrossClimate and all-season tyres are only available in certain 18in tyre sizes and below, so if you drive a performance vehicle, or a heavier car with larger wheels, they simply aren't an option.
Jonathan Benson is the founder of www.tyrereviews.co.uk, and has worked as an independent tyre tester since 2006
Got a motoring question? Our experts are standing by to help, just tweet us your question using #askwhatcar
For all the latest reviews, advice and new car deals, sign up to the What Car? newsletter here