Last word on driving in winter
The argument on front- and rear-wheel drive cars and the benefits of winter tyres is wrapped up here by letters from two readers, writes Campbell Spray
Published 16/01/2011 | 05:00
I HAD a huge response to the article and letters last week regarding driving in snow and the use of winter tyres. Here are two more letters which seem to summarise both sides of the argument, although I am getting suggestions the whole time about how to cope with freezing conditions. A colleague says that a friend with a Mercedes never travels without a couple of bags of cement in the boot to weigh the rear wheeels down.
I feel I must add to the debate on rear-wheel drive weaknesses in winter conditions. Firstly, the debate should not be just about BMWs since they are not the only rear-wheel drive cars -- Mercedes and Lexus being the other prominent makes. BMWs are no worse or better than other rear-wheel drive cars on snow or ice.
However, despite BMW claims, rear-wheel drives are not only much more unstable on snow/ice but can also be downright dangerous. I have to date owned 14 different cars, two of which were rear-wheel drive (RWD) and two four-wheel drive, the rest being front-wheel drive (FWD). Rear-wheel drives are comparatively much poorer performers on snow/ice for two main reasons:
1. No engine weight over the driving wheels leading to poorer traction than FWD.
2. There is much more control when front wheels are 'pulling' the bulk of the weight of the vehicle behind them. Conversely, there is much less control when rear wheels are trying to 'push' the bulk of the vehicle in front of them and the front wheels might be trying to make a direction change. With FWD, when, say, turning right, the wheels driving the car face in same direction, which is much better than the dynamics of RWD.
It's a bogus argument for BMW to peddle winter tyres in Ireland for €1,000 and claim that RWD isn't the problem, and "it's the tyres". The FWD cars don't need them, so how can BMW explain that? If you put winter tyres on both a FWD and RWD car, the FWD will be much better on snow and ice.
I had a C Class Merc for four years up to last year (which I loved for the most part) and I am very experienced at driving in snow. It was a disaster compared to an FWD car, even though it did have traction control. The biggest risk driving a RWD car is that the rear will swing out and you lose total control. This does not happen to FWD cars.
On top of this, if driving with no passengers in the rear, there is poor traction due to the lack of weight over the wheels. How many executives had to leave their Mercs or BMWS at home and bring their wife's little runaround to work because as an FWD, it had better traction and could get out of the drive when the expensive RWD couldn't. This is a serious problem for Mercedes and BMW as it looks like we will be getting hard winters from now on.
It is also a case that when driving in greasy conditions, RWD cars are dangerous if driven hard out of corners, even with traction control. This has been the cause of many accidents in crew-cab and full-size jeeps which run in back-wheel drive when 4WD is not engaged. I accept that RWD cars give a lovely drive and very responsive steering but they are only suited to experienced drivers who are aware of the dynamics of RWD.
My advice to people driving RWD cars in snow and ice is to put five cement blocks or the equivalent weight in the boot of the car to increase traction.
I drive a new Outlander now and the 4WD is great in wintry conditions. Audi Quattro or Subaru are the most common 4WD cars and also a winner in these conditions, even if MPG suffers.
Regards, James Gorman
PS. I forgot to say that if I was driving a RWD, I would carry a small electric pump and I would reduce the air in the tyres down 15lbs of pressure and they will grip better if stuck or driving slowly on very bad roads. You can pump the tyres back up to 35lbs when free of the snow.
I read your article re winter tyres with great interest. In November last year, we fitted four Bridgestone Blizzard winter tyres to our BMW 530d Touring. The result is incredible! The car is fantastic with the winter tyres; in fact, it is better than the Ford Focus (diesel) we also have when driving in either snow or ice. Several tyre dealers we contacted were unable to source winter tyres for us here in Ireland so we bought a set over the internet from Germany (delivered in 48 hours).
Bottom line -- winter tyres definitely work and should be considered mandatory.
Feargal O Cinneide
I think that concludes the debate for the present. However, I will keep all suggestions on file for later use.