As temperatures drop every winter, drivers face the dilemma of whether to switch tyres. From a safety angle, swapping to winter tyres is a no brainer, but investing in a second set of rubber can be a tough call financially. So what about a tyre that can perform almost as well as specialist summer and winter designs throughout the year?
All-season tyres make up a small slice of the UK market, but that proportion is growing – and manufacturers have sat up and taken notice, with new products from Pirelli, Michelin, Goodyear and Nokian launching this year.
• See our comprehensive Winter tyres test 2014/2015
Many brands believe these are the answer to Britain’s erratic weather and drivers’ reluctance to invest in a second set. But how do these tyres stack up? In a UK magazine first, we tested six all-season designs. Then, to see what compromises (if any) you have to make as a motorist, we compared them to the best-performing winter and summer alternatives from our previous tests.
To find the best all-season tyre, we headed to Nokian’s ‘White Hell’ proving ground in Ivalo, Finland, for the snow tests, then performed the cold, wet and dry assessments at Continental’s Contidrom facility just outside Hanover in Germany. Unfortunately, Michelin’s new CrossClimate “summer tyre with winter capability” was launched just too late to be included.
• Tyre reviews: best tyres 2015
We tested the 205/55 R16 size found on a wide range of big-selling family cars to name our winner.
What we tested
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The six contenders for our first all-season tyre test are listed below, and an immediate indication that they’re different to our winter test is their V speed ratings (up to 150mph), rather than the usual H (up to 130mph) on 205/55 R16 winter tyres. Only the Nokian had an H speed rating. Weight ratings were mainly 91, with just two tyres at 94.
We also list tyre label ratings for rolling resistance, the key factor in fuel economy (FE), plus wet grip (WG) and ‘pass by’ noise (N). Fuel economy and wet grip are ranked A-G, with A the best. Noise is in decibels – the lower the figure, the quieter the tyre.
Bridgestone A001 - Ratings: 91 V (FE) F (WG) B (N) 72dB
Goodyear Vector 4Seasons Gen-2 - Ratings: 94 V (FE) C (WG) B (N) 68dB
Maxxis Allseason AP2 - Ratings: 94 V (FE) E (WG) B (N) 69dB
Nokian Weatherproof - Ratings: 91 H (FE) C (WG) A (N) 69dB
Pirelli Cinturato All Season - Ratings: 91 V (FE) C (WG) B (N) 69dB
Vredestein Quatrac 5 - Ratings: 91 V (FE) C (WG) C (N) 69dB
Winter tyre: Continental ContiWinterContact TS 850 - Ratings: 91 H (FE) C (WG) C (N) 72dB
Summer tyre: Dunlop Sport BluResponse - Ratings: 91 V (FE) B (WG) A (N) 68dB
Picking a top all-rounder
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The way we pick our overall winner lets you focus on the factors you care about most in a tyre. Each all-season design is tested in 13 key criteria (below), plus price, and gets a percentage score in each category – the top performer in each test scores 100 per cent, with the rest rated relative to this.
We add up these percentage scores, but each assessment has the same value in the overall final result. So tests where there’s a big gap between the best and worst tyres – such as aquaplaning – have the same effect on the final outcome as those where the difference is small, like dry handling.
Snow circle
At Ivalo, we pick a line just off the centre of the ice and increase the speed until the car starts to run wide. Final result is based on an average of several lap times and rates the pure lateral grip generated by each tyre without braking or traction playing a role.
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Snow traction
Key for many motorists who drive within the limits of a summer tyre, but struggle on icy hills. To rate the chances of reaching the top, we hit the throttle from walking speed with the traction control on and measured the distance until we made it to 25mph.
Snow braking
The biggest fear for drivers in the snow is when the car just can’t be slowed. To gauge how much grip each tyre generates, we repeatedly braked from 26mph and measured the distance taken to drop to 3mph, removing the variations of the last few metres when coming to a halt.
Snow handling
We tested as you’d drive with the electronic stability control still on, but turned down to allow differences in tyres to be revealed. On the tight turns and fast sweeps of the undulating handling course, average lap times were taken to find a winner.
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Wet braking
Unseasonable weather at the Contidrom saw us performing this test at temperatures around seven degrees Celsius – the point where you’d switch between summer and winter tyres. Still, this was the same 50mph braking assessment as we’ve done before, and we took an average to get our result.
Wet handling
Another assessment carried out at the performance crossover point between winter and summer tyres. We took an average of lap times around Continental’s carefully designed wet handling track, which combines fast sweeps with quick direction changes and tight turns.
Wet circle
As with the snow circle test, this measures the pure lateral grip generated by each tyre without aquaplaning or traction being involved. Prop yourself against the passenger seat, hug the inner kerb then increase
speed until the line can no longer be held. Our result is based on average lap times.
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Straight aquaplaning
Temperature has no effect on how tyres handle deep water; that is down to the tread. We accelerated hard with one of our test car’s wheels in 7mm of water. Sensors record the spin on both wheels and measure the speed when the one in the water exceeds 15 per cent of the other – the point when grip is lost.
Curved aquaplaning
Again, temperature plays no role in how well the tread copes with standing water while distorted through cornering. A g-meter measures loss of lateral force as the car is driven through a flooded strip on a tarmac circle at increasing speeds until grip is lost.
Dry braking
This is key for all-season tyres as it reveals what performance, if any, is lost through the dry summer months. We measured stopping distances from 62mph over an average of 10 runs, removing any extreme results.
Dry handling
Another test that reveals the compromise you make on dry roads with an all-season tyre over a summer design. The long, high-speed sweeps of the Contidrom handling track push the softer all-season compounds to
the limit. Result is an average of lap times.
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Noise
while the noise ratings published on tyre labels refer to ‘pass by’ noise, drivers want tyres that are quiet inside the car. So we recorded noise levels while coasting from 50mph over smooth and rough tarmac, plus concrete. We took an average reading on each surface and overall to get the result.
Rolling resistance
Fuel prices may have dropped recently, but running costs are still important and this test measures how much a tyre will ultimately set you back at the pumps. The easier a loaded tyre rolls, the less fuel is required. Around a five per cent drop in rolling resistance equates to a one per cent reduction in fuel economy.
Price
Tyres should be chosen on performance, not price, so this is the only part of our tests that we weight. It plays a small part in the overall results, and the figures are from Black Circles – Best Site in our previous test of online tyre retailers.