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[YesAuto four-wheel drive detailed explanation] “quattro”, the name representing Audi's four-wheel drive system, is one of Audi's most resounding signs. It helps the racer to conquer the field, and can also provide the driver with more stable handling performance. Quattro has a high penetration rate in Audi's car series, but their structure is different. Today we introduce the quattro four-wheel drive system on Audi's SUV. The protagonists on the stage are Audi Q3, Audi Q5 and Audi Q7 ( The following text is abbreviated as Q3, Q5, Q7).

Audi Q3

Audi Q3 2015 35 TFSI quattro comfort type

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Manufacturer's guide price

356,800

The domestic Audi Q3 currently on sale is divided into 30 TFSI models equipped with 1.4T engine and 35 TFSI and 40 TFSI models equipped with 2.0T engine. Only the high-end 35 TFSI and 40 TFSI models have four-wheel drive versions. The models we are testing today are 35 TFSI quattro Comfortable.

Q3 uses a four-wheel drive system based on a transverse engine. The multi-disc clutch placed at the front end of the rear axle achieves torque distribution between the front and rear axles through changes in internal oil pressure. The limited slip between wheels relies on electronic assistance.

A friend asked, this four-wheel drive system that uses a multi-disc clutch to distribute the power of the front and rear axles is a timely four-wheel drive structure. Why is it divided into a full-time four-wheel drive? In fact, the Q3, like the Tiguan, has a certain percentage of power distribution to the rear wheels during normal driving, about 5%.

Power distribution test between shafts

The test of the two sets of open pulleys is the simplest project we have set up. This project did not form a big test for the power distribution of the front and rear axles. Whether the two front wheels or the two rear wheels lose adhesion, the Audi Q3 can pass smoothly.

Cross axis test

We have increased the difficulty and adopted a cross-shaft test with one wheel slipping on the front and rear axles. In this test, in addition to testing the power distribution capability of the front and rear axles of the four-wheel drive system, the limited-slip effect of the electronic system's braking is also crucial to the results. Importantly, in this test, the Audi Q3 passed very reluctantly. The reason is still due to the electronic system. It still does not brake the wheels in time and force enough, and the slippery wheels have been slipping crazy there. To be honest, whether or not it can pass in the end is all “at a thought” of the electronic system.

Single wheel landing test

In the three-pulley test, only one wheel has adhesion. For most urban SUVs, it is not easy to get out of trouble in this test. Even with the quattro name, I guess the three pulleys will still be difficult for Q3.

Because the power output of the Audi Q3's four-wheel drive system is more inclined to the front wheels, we start with the less difficult one-sided front wheel landing. From the video, we can find that the electronic system of the Audi Q3 can hardly be seen to brake the slippery wheels, so the power is lost by the slippery wheels, and the power allocated to the wheels with adhesion is not enough to get the car out of the trap, so the Audi Q3 cannot pass Three pulley block test.

We can also foresee that the single rear wheel has adhesion. The power transmitted to the adhesion tire will only be less, so it will also fail the three-pulley test.

Summary

Advantages: The four-wheel drive structure is simple, and the electronic system can automatically adjust the power output of the front and rear axles according to the current driving state.
Disadvantages: This four-wheel drive system is more focused on urban driving, and its ability to escape difficulties under extreme conditions is not strong enough.

As Audi's entry-level SUV, the cross axle is the upper limit of the ability of the Audi Q3 four-wheel drive system. For this kind of urban SUV, this kind of performance is also in line with its positioning, and it is not unacceptable. To cope with some conventional off-road conditions and to ensure that they are out of trouble under normal circumstances, it can meet the daily needs of most users who buy this type of luxury compact SUV.

Audi Q5

Audi Q5 2013 Model 40 TFSI Technical Type

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Manufacturer's guide price

427,600

The domestic Audi Q5 currently on sale all use a 2.0T engine, which is matched with a 6-speed manual gearbox or an 8-speed manual gearbox, and all are equipped with a quattro four-wheel drive system. What we are testing today is a 2013 model with 40 TFSI technology.

Unlike the Audi Q3, the Audi Q5 uses a longitudinal engine. The core of the four-wheel drive system is the Torson type central differential integrated in the gearbox. It can automatically adjust the power distribution of the front and rear axles according to the torque difference. It is purely mechanical The type structure also guarantees its response speed and durability.

Power distribution test between shafts

Cross axis test

For the Q5 with the Torson central differential, the power distribution test between the axles did not cause any difficulty for it. The two front wheels, two rear wheels skid, and even the cross axle test, the Audi Q5 can pass smoothly, we still see Let's take a more difficult three-pulley test.

Single wheel landing test

First of all, only the left front wheel has adhesion. From the video, we can see that the electronic stability system brakes the slipping wheel in a timely manner. After about two or three seconds, the adhesion wheel has enough power to help the vehicle get out of trouble. , Did not form too many obstacles to Q5, the performance was satisfactory.

After that, we only made the right rear wheel have adhesion. At this time, the Q5's escape process was not as smooth as when the front wheel had adhesion. The right rear wheel on the road was always ready to move, but in the end it passed the test item.

Summary

Advantages: The allocation level of the four-wheel drive system is sufficient to cope with most road conditions.
Disadvantages: The electronic system does not brake the slippery wheels very quickly, and the extreme state escape may still be affected.

We are very pleased to see that Audi's “walking” Q5 has a considerable ability to get out of trouble. Although it was a bit reluctant to test the three-wheel group with single rear wheel adhesion, its performance has exceeded most SUVs. In the face of most road conditions, car owners can safely pass, but pay attention to the Q5's ground clearance, don't support the bottom.

Audi Q7

Audi Q7 2015 Model 40 TFSI Exclusive Collection

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Manufacturer's guide price

1.2398 million

Audi Q7 is the top SUV under Audi. The models currently on sale are equipped with a 3.0T supercharged engine, which is divided into 35 TFSI and 40 TFSI according to different powers. It is equipped with an 8-speed manual transmission. Today we are testing the 40TFSI Zun Tibetan type.

Audi Q7 and Q5 adopt the same four-wheel drive structure, and both are full-time four-wheel drive systems based on the Torson central differential structure. Under normal circumstances, it will transmit power to the front and rear axles at a ratio of 40:60. When encountering special road conditions, the front wheels can be allocated 15% to 65% of the power as needed, and the rear wheels can be allocated 85% to 35% of the power accordingly.

Power distribution test between shafts

Cross axis test

In the power distribution test between the axles and the cross axle test, the situation of the Audi Q7 is the same as that of the Q5. The difficulty of the test is too easy for it. We will not go into details and directly analyze the three-pulley test.

Single wheel landing test

Q5 can complete the three-pulley test, Q7 is naturally no problem. From the video, we can see that Q7 is obviously much more relaxed when passing three pulleys than Q5. The electronic system effectively restrains the slippery wheels, and does not make them spin crazy, so the power transmission to the wheels with adhesion will be more relaxed. It is more direct and effective. Compared with Q5, Q7 has a significantly faster escape speed.

Summary

Advantages: No matter whether it is used in the city or out of trouble in the field, this four-wheel drive system of Q7 has a very good performance.
Disadvantages: If there is another low-speed four-wheel drive gear, it will be even more powerful.

Audi's flagship SUV did not let us down. It steadily and neatly passed the most difficult three-pulley test and reached the level it should be. In the part outside the test, the Audi Q7 is also equipped with an air suspension, which can raise the body when necessary to enhance the passage of the vehicle. If the car owner wants to go to the wild, as long as it is not in the extreme state, the Audi Q7 is adequate.

Full text summary

    At this point, we have sorted out the four-wheel drive performance of Audi's SUVs. From the results, the Q3 with a horizontal engine platform and a multi-disc clutch-type central differential is relatively inferior in four-wheel drive performance. It can only be crossed Axis test. The performance of Q5 and Q7 is satisfactory enough, and both have passed the three-pulley test. From the point of view of the process, the Audi Q7 should be smoother. Of course, this difference in performance is also in line with their respective positioning.