No matter which brand of 4S store you are in, the most popular ones are often SUV models. Although we always say that SUVs have no bright spots compared to cars except for space and passability, many people come here for its passability. At this time, whether there is four-wheel drive has become an important indicator that affects many people’s car purchases.
For most people, four-wheel drive means four-wheel drive, but it is not enough for you to know that it is four-wheel drive, because there are many types of four-wheel drive. Today, I will give you a popular science about our common four-wheel drive system.
4WD
Many SUVs we can buy now have four-wheel drive models to choose from. Generally, they will also be specially marked on the body, such as AWD and 4WD. Let’s talk about 4WD first. It is the abbreviation of 4 wheel drive. The translation is Four-wheel drive system. The Beijing Jeep back then actually used 4WD, but Beijing Jeep is generally written as 4X4, but they are actually one thing.
Since both the 212 and the Beijing Jeep Cherokee used 4WD, it is enough to show the level of this four-wheel drive system. Its usefulness is not only as simple as getting up and down the road, but generally 4WD models have good off-road capabilities.
Take the most primitive 212 as an example, we can see that there is a small gear next to its gear handle, this thing is the unique transfer case of 4WD. The power is output from the engine and enters the transfer case, which distributes the power to the front and rear differentials, and finally to the wheels.
And this system has a big advantage, that is, it can completely lock the four wheels and provide enough power to achieve the purpose of getting out of trouble or going off-road. However, it also has disadvantages. This system must be turned off when driving on paved roads, because if the transfer case is in a combined state, the speed of the four wheels will remain the same, so that the inner wheels and outer wheels will not have the same speed when turning. The speed is poor, making it difficult to turn.
AWD
Let’s talk about AWD, which is the abbreviation of All Wheel Drive, which translates to full-time four-wheel drive. Maybe you will say, what is the difference between this and 4WD? As we said earlier, 4WD needs to disconnect the transfer case when driving on paved roads, and the difference with AWD is that it is a four-wheel drive system that works all the time.
A general AWD system will be equipped with front, middle and rear three sets of differentials, and their function is to distribute power to the four wheels in different proportions according to different situations. It can be seen that AWD is to make all four wheels provide the best traction to the car to improve driving performance. Based on this working principle, the effect of AWD system will be more obvious in rainy and snowy weather.
At present, our common AWD is more electronically controlled. Various sensors are added to the ordinary mechanical system to obtain data such as wheel speed and torque. Through the analysis of these data by the ECU, the engagement of the electronically controlled clutch is controlled. So as to achieve the effect of distributing torque in different proportions.
The famous Audi Quattro is a kind of AWD. The performance of the Audi racing car equipped with the Quattro system in the field can be said to be impeccable. In fact, seeing this, I believe many people can understand that although the names are similar, AWD and 4WD are two different things.
Although they are all four-wheel drive, the former focuses on improving driving ability, while the latter is born for off-road. To put it simply, AWD is prepared for those urban SUVs. It can significantly improve the driving performance of the vehicle, and at the same time help to some extent, while 4WD is more common in hard-core off-road vehicles.
As for how to choose them, it is actually very simple. It is enough for an urban SUV to have AWD, which can bring a lot of help to your driving in rainy and snowy days. As for 4WD, it is only needed for serious off-road vehicles.
Content source: SUV driving.
