Four-wheel drive – how does it work, for whom is it, in which models can you find it

The four-wheel drive is a solution valued by many drivers. What’s important is that it’s installed not only in the off-road cars, but also in SUVs, crossovers, family vans, and even in sedans and compacts. How does the four-wheel drive work, and are its advantages and disadvantages? Details below.

 

What is the four-wheel drive?

The four-wheel drive is a drive used in various cars, which by means of the driver’s actions or automatically adds drive to the other axle – the one that in usual conditions does not operate. In effect, the driving force is distributed on all four wheels, in the same proportion. This provides better grip, and also safety and the driving quality in bad weather conditions, such as slippery surface.

 

Types of the four-wheel drive

The four-wheel drive is available in various versions – there is the constant one, the one with center differential, one manually activated by the driver and one activated electronically. Each of them has its advantages and disadvantages, although the most popular one is the automatic version. It’s the cheapest to manufacture and also it doesn’t influence the fuel consumption. In this case, during normal exploitation, when good grip is maintained, the power engages only one axle – usually the front one. This in turn results in the system not being constantly engaged. The driving force reaches the rear wheels only when the grip is weaker, which allows gaining better stability on a snow-covered and icy road. It’s also useful e.g. during driving on muddy ruts, but not only then.

What should you know about the mentioned types?

 

Constant four-wheel drive

The first type of the four-wheel drive is the constant four-wheel drive in which torque is always distributed on both axles, as a result of which the power is always transferred to all four wheels. It’s possible thanks to the center differential. The constant four-wheel drive can be found in models such as the Audi Allroad, Mitsubishi Lancer Evolution and Pajero, Toyota Land Cruiser and Land Rover Discovery.

 

 

The constant four-wheel drive can be divided into symmetrical and non-symmetrical. The symmetrical one can be found in the Land Rover Defender, in which the torque is distributed on both axles simultaneously. The non-symmetrical variant features the torque distribution between the axles according to the need, by means of the inter-axle differential or the multi-plate clutch.

An advantage of this solution is better predictability of the behaviour of the vehicle in changing road conditions. This system greatly influences the weight of the vehicle – all the elements weight in sum over 150 kilograms. It’s important to bear in mind that depending on the car model, servicing might be problematic, which in effect might be also more expensive.

 

Manual four-wheel drive

There is also a manual version of the four-wheel drive. In this case, one axle is powered in a constant manner, and the drive of the other axle can be manually activated with the use of a lever or a button. The manual drive can be found i.a. in Suzuki Jimmy, Jeep Wrangler and Nissan Patrol, in which the real axle is constantly powered, and the front axle can be engaged separately. However, it’s good to use this option only in off-road. On normal surface the four-wheel drive which works this way would rather bother than help you. Drivers must remember about it – the drive should not be activated when riding on asphalt, because intense stresses occur, and despite the nigh durability of the system – failures might happen. Additionally, the ride might not be easy – driving with such system not only generates specific noises, but also makes turning difficult.

 

Automatic four-wheel drive

The third type of the four-wheel drive is the automatic one. This solution is an intermediate between the constant four-wheel drive and the manual one. This type of the four-wheel drive can be found in the off-rad cars, as in i.a. Mitsubishi Outlander, Toyota RAV4, Volvo AWD, Suzuki SX4, Audi A3 and BMW X5. In this variant, the four-wheel drive is constant and it’s directly transmitted to one axle, and by means of the multi-plate clutch it is also transmitted to the other axle, according to the need. As it has been mentioned before, this system is not equipped with the center differential – it is equipped with the multi-plate clutch, which is located near the differential mechanism of the rear axle. As a result, if the computer responsible for controlling the drive figures that it is necessary to activate the real wheel drive – the clutch does it. What’s important is that the electronics tightly cooperates with the ABS sensors, which in turn allows it to estimate how much of the haldex torque is transmitted to the rear wheels. The whole system makes it possible for the real axle drive to be activated incredibly smoothly, unnoticeably for the driver.

 

 

Four-wheel drive – advantages and disadvantages

It’s true that generally a car with the four-wheel drive is more universal than the cars with a single-axle drive. This applies to both the variety of surface and the weather conditions. You can definitely drive further with a car equipped with the four-wheel drive than driving a car without it. However, it doesn’t mean that you can always reach any destination. The four-wheel drive of course provides better grip than the single-axle drive, but when the car starts to skid, then it might be very difficult to control it. When it comes to the cars with the four-wheel drive, an understeer skin might smoothly transition into an oversteer one, which substantially makes it more difficult to control it.

It’s no secret that the cost of a car with the four-wheel drive is substantially higher, compared to a car with a single-axle drive. Cars with the four-wheel drive are also more expensive to maintain. You visit gas stations more often, especially if you choose the constant four-wheel drive. This system usually makes the car heavier, which increases the fuel consumption. The costs of repairs are also higher. That is because this system is complex, which, as any other part of the car, sooner or later will need repairing.

Therefore, the decision to buy a car with the four-wheel drive must have other justification than economy. Such car can be definitely useful for people who often travel through difficult terrain, e.g. they live or work in the mountains or forest, or for tourists who regularly visit the highest situated ski resorts. In passenger cars with the fur-wheel drive the vehicle stability is better, which in turn allows easily reaching destinations in difficult conditions. As a result, these cars will perform better in autumn and winter, when rads are covered with wet leaves, snow, and ice, and when drivers ride on unhardened surfaces covered in mud. It’s good to keep in mind that cars with the four-wheel drive have higher suspensions, which makes them perfect for driving on uneven and demanding roads.

Another great advantage of cars with the four-wheel drive is that they maintain their value better. Cars of this kind require higher financial means to spend on their purchase, but when you decide to sell it after some time, you’ll have an opportunity to regain a bigger part of the invested money.

 

Cars with the four-wheel drive available on the market

To finish our article, let’s take a look at the new cars equipped with the four-wheel drive. To do so, let’s visit one of the Polish advertisement services. Let’s first take a look at the cars which have the constant four-wheel drive:

• Audi A5, A6, A7, Q2, Q3, Q5 and Q7;
• BMW 4, 5 and 7 series, as well as X1, X3, X4 and X5;
• Mercedes C-, E- and S-class, as well as the CLA, GLC, GLE and GLS models;
• Volkswagen Amarok, Golf, Multivan, Tiguan, Touareg;
• Subaru Levorg, Forester, Outback and XV;
• Mini Clubman, Cooper S, Countryman;
• Jeep Grand Cherokee.

When we change the filter to display vehicles with the automatic four-wheel drive, we can see models of the manufacturers such as: BMW, Audi, Volvo, Volkswagen, Mercedes, Porsche and Honda. The least numerous are the cars with the manual four-wheel drive. We can find brands such as: Nissan, Mitsubishi, Toyota, Suzuki, Jeep, Isuzu and Hyundai.

Overall, the range is wide. Of course, the secondary market also has a lot to offer. However, remember to avoid offers of used cars with the four-wheel drive for a few thousand zloty. Low price usually indicates that soon after purchasing the car you will leave tons of money at a repair shop.