Question Topic: Safety margins
Four-wheel-drive improves the traction you have on the road as both sets of wheels can be fully engaged. When you drive with all four of your wheels, your vehicle has the maximum amount of grip on the road. The extra traction also gives you more control when driving in dangerous conditions, such as in icy, snowy, or off-road areas. Typically, four-wheel-drives will also be heavier than two-wheel drive vehicles which has the by-product of improving your grip and traction on the road. Nevertheless, you should drive with equal caution as four-wheel drive alone does not mean you will drive safely.
Are there any downsides to four-wheel drive?
Whilst four-wheel drive gives you extra grip on the road, there are also some downsides you should be aware of:
- Four-wheel-drives tend to be more expensive from initial purchase through to maintenance and repair.
- Four-wheel-drives usually consume more fuel due to the fact they tend to be heavier vehicles.
- Four-wheel-drives are usually heavier and braking distance is increased in heavier vehicles. This means it will take longer for you to come to a complete stop.
- Lighter vehicles can avoid collisions easier than heavier vehicles.
- Four-wheel-drives may encourage overconfidence in the driver which can increase the risk of accidents.
Theory Test Question
Have you answered the question: What’s the main benefit of driving a four-wheel-drive vehicle? Let’s take each of the answers one by one to check what you have learnt:
Improved grip on the road
Correct! Four-wheel drive engages both sets of wheels which gives you more traction on the road. When used appropriately they are suitable for more challenging road and weather conditions.
Improved passenger comfort
Wrong! Whilst some four-wheel drives may offer additional comfort, this is not their main benefit which is additional grip on the road.
Lower fuel consumption
Wrong! Four-wheel drives tend to use more fuel because they are usually heavier vehicles than two-wheel drives. Fortunately, this extra weight gives them more grip on the road which is their main benefit.
Shorter stopping distances
Wrong! Four-wheel drives are normally heavier than two-wheel drives so will usually have longer stopping distances. They will only have an equivalent stopping distance to cars with a comparable weight and specification.
In section 22 of the official DVSA guide to driving, it states:
Four-wheel drive is where both axles of a vehicle are driven by the engine. The system may be permanently connected, or drive to the second axle may be selected by the driver to suit the conditions.Four-wheel-drive vehicles are available in a variety of models, including offroad designs, estate cars, sports vehicles and saloons.
Vehicles that use a four-wheel-drive system by default are known as all-wheel drive (AWD). In most cases, the driver can’t switch into a two-wheel-drive mode. Standard four-wheel drive differs from AWD in that four-wheel drive is selected by the driver, generally in response to situations where low traction is likely, such as on slippery surfaces.
You don’t need any extra skill to drive four-wheel-drive vehicles on public roads. However, you should be aware that some large four-wheel-drive vehicles have blind spots that can easily obscure a group of pedestrians, a motorcyclist or even a small car.