Wednesday, November 13, 2013

Winter tyres

Winter Tyres or 4x4: which is best? - Auto Express (04/nov/2013)

"Winter tyres are going to be on a lot of minds this year - Britain could face a particularly harsh winter this year, with snow falling from as early as November. If you've got a four-wheel drive car, you probably think you're properly prepared - but are you? We went up to Tamworth Snowdome to find out if a front-wheel drive car with winter tyres has more traction in the snow than a 4x4 with summer tyres fitted. We used two Ford Kugas, both with 2.0-litre diesel engines and manual gearboxes - but one is front-wheel drive, and the other all-wheel drive. The 4x4 Ford Kuga costs £1500 more than the normal model. In snowy conditions the rubber in summer tyres gets harder and less grippy. Winter tyres use a softer compound, and a tread pattern that's designed to pick up snow - improving grip in these harsh conditions. In our first test we saw that the front-wheel drive car on summer tyres was hopeless in the snow - but when fitted with winter tyres, it obviously did much better. However we also tested the 4x4 on summer tyres - and the results might surprise you. With winter tyres, the normal Kuga went 110 metres up the slope, while the 4x4 car only made it 13 metres up, before sliding back down 9 metres. in the end, it ended up no further than the standard did with summer tyres. We also tested the four-wheel drive Ford Kuga with winter tyres - and the difference was astonishing. There was plenty of grip and the car drove all the way to the top of the steep ski slope without a problem. Obviously, the best solution for driving on snow is to have a 4x4 on winter tyres - without the right rubber, a 4x4 is just as useless as a two wheel drive car. Having four-wheel drive won't help with braking, though - and that's much more important."

Winter Tyres v Summer Tyres: the Truth! - Auto Express (17/nov/2011)

 "British motorists tend to run summer tyres on their cars all year round, regardless of the weather. However, as our exclusive comparison test shows, this can be very dangerous.

We headed to Sweden to compare the performance of summer tyres with winter tyres on snow ­ and the results were quite shocking."

BMW Winter Tyres. (14/nov/2012)

"As temperatures drop below 7oC, see how BMW Winter Tyres ensure maximum levels of safety and performance this winter."

BMW X3 Winter Tyres 2011 (28/oct/2011)

"Following two of the worst consecutive winters in living memory BMW has revised its specialist winter tyre programme, designed to help drivers get the best on-road performance from their car throughout the winter months -- regardless of weather conditions. Changing tyres to suit different seasons is already part of mainstream motoring in most of Europe and now BMW are making this easier than ever to do in the UK too. As well as offering a selection of winter wheel and tyre packages, for just £30 BMW UK will store and insure the spare set of summer wheels and tyres until they need to be changed again in spring. Summer tyres, fitted as standard equipment by all car manufacturers, operate best at temperatures above 7°C. This means summer tyres fitted by BMW provide excellent levels of grip, acceleration, braking, comfort and fuel economy in normal road conditions. However, once the outside air temperature gets nearer to freezing the rubber in summer tyres hardens, which detracts from their performance. In true wintry conditions of snow and ice tyre performance is even worse. Developed by BMW the new winter wheel and tyre packages have been specially engineered to operate much better than summer tyres at temperatures below 7°C. The tyre is made from a different mix of silica / rubber compound which enables them to retain flexibility at much lower temperatures, generating heat and reaching their optimum operating temperature much more easily. Fitting winter tyres will ensure that a BMW performs to the best of its abilities during severe weather, yet even if the winter is mild, winter tyre users will benefit from significantly reduced tyre wear and increased wet weather grip and performance. Potentially there is a cost benefit too. The new BMW winter wheel and tyres can result in as much as 40 per cent* better wear characteristics than summer tyres when the outside temperature is below 7°C -- meaning the tyres will last a lot longer. Winter tyres also feature an increased number of blocks, channels and sipes which ensure they dissipate standing water more effectively, helping them to reduce the risk of skidding on wet surfaces. This sophisticated tyre technology ensures maximum levels of grip over winter, significantly reducing the chances of an accident, whatever the conditions. Braking distances improve by up to 20 per cent on icy roads and up to 10 per cent in the dry."

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