How we pick an all-round winner
AS ever with our tyre tests, each design is assessed over a number of key criteria, allowing you to focus on the area that’s most important to you when buying. There are 13 categories, but we’ve put the emphasis on wet performance, with snow grip counting for a smaller, but still essential, part. Price makes up a small element of the overall ranking.
The scores for each test rate the winner at 100 per cent, with the rest ranked relative to that. Then, to calculate the overall champ, we add up the scores, and weight them to ensure that a test with a big difference in performance counts for the same as one in which the tyres are evenly matched.
To ensure we test what you can buy, we ask the makers to nominate a tyre, which we then purchase. However, stock problems meant this wasn’t possible with Falken, Kumho, Nexen and Toyo.
THIS test replicates that heart-stopping moment when you hit the brakes while driving on snow and all you get is a juddering from the pedal. We do a series of maximum-braking stops from 26mph, measuring the distance taken to decelerate to 3mph, then take an average to form the overall result.
WE do this test, which assesses how likely you are to get up that snow-covered hill, at the same time as the braking test. In it, we measure the distance taken to accelerate from 3mph to 26mph using traction control. We start at walking pace then accelerate at full throttle. An average makes up the result.
PURE lateral grip is measured here without other factors, such as acceleration or weight transfer, playing a part. The test circle has a diameter up to four times bigger than that of the wet test, but the technique is the same. Tuck the nose in to the inner edge and accelerate until it runs wide. An average of lap times is used.
THE handling track is a real test for tyres because it combines big elevation changes with tight turns and open sweepers. Climbing turns expose any traction problems. An average of lap times is used and the circuit is graded after each run to ensure conditions are the same.
OUR aquaplaning tests measure how well tyres cope with deeper water and how effectively the tread pumps out water from under the tyre. The car is placed on a rail system with one wheel in water. It is then accelerated hard until the tyre is spinning 15 per cent faster than the one in the dry.
A FLOODED strip on a large tarmac circle is at the heart of this test, which looks at how well tread works when cornering. The car is lapped at ever-higher speeds with lateral G measured as it passes through the water. The test is completed when all grip is lost.
THIS test is temperature-sensitive, so we do it in winter and summer conditions. We do multiple stops measuring the distance taken from 50mph using the rail system, which ensures the same piece of track is used each time. The cold temperatures were a little higher than ideal this year, but were still less than seven degrees Celsius.
LIKE wet braking, wet handling is affected by temperature, which is why winter tyres have different compounds from summer versions. Again, as with the braking test, we rate this separately at above and below seven degrees Celsius, then take an average of the lap times around the track.
AS in the snow circle examination, this test provides a measure of the lateral grip each tyre can generate, this time in the wet. Lap times are at the heart of the rating, so we do multiple laps with the nose of the car tracking the inner kerb, accelerating until the line can no longer be held.
OUR tests are done in spring or summer temperatures, although the test is not as sensitive to heat as the wet version. Several stops from 62mph are averaged out to get the final result.
WE measure lap times around a 1.6km section of the handling track then take an average. The section provides fast direction changes and long turns where the tyres are heavily loaded.
THIS test measures the force required to turn a tyre, which directly affects your car’s fuel economy. The more power needed, the more fuel required. Our test is done to industry standards with an average of two tyres used. To calculate the difference between two tyres, a five per cent change in rolling resistance roughly equates to one per cent in fuel economy.
THIS is not the same test as that used for EU tyre labelling, which measures pass-by noise. Our examination is carried out inside the car with a sound meter measuring noise levels as the car coasts from 50mph over three surfaces.
OUR figures are supplied by the winner of our test of online tyre retailers, Black Circles. The figures are fully fitted prices and are what the company charges (or would charge if a tyre is not part of its range). It plays a small part in the result because the emphasis is on performance.
SNOW TESTS: Tyres are rated on how quickly they can stop, accelerate and turn car on the white stuff