Mercedes-Benz G-class is almost synonymous with hard-core off-road, but under the vigorous wave of electrification, can Mercedes-Benz big G still sit firmly in the front row? This depends on the ability of Mercedes-Benz pure electric G-class. Approaching the Beijing Auto Show, Mercedes-Benz debuted a pure electric G-class off-road vehicle. The square box shape, the four-wheel wheel side motor, the in-place U-turn, etc., everything is so familiar from the design to the performance. So what is the difference between the Mercedes-Benz pure electric G-class off-road vehicle?
Playing pure electric can also achieve "low turn and high torque"?
The first thing worth playing is the performance, the Mercedes-Benz pure electric G-Class off-road vehicle has a maximum power of 432kW and a maximum torque of 1164Nm. You know, this is the performance of four motors. If its torque is top-notch, then its power performance can only be considered mediocre. For reference, the U8 has a combined system torque of 1,280 Nm and a combined system power of 880 kW. The tank 700 plug-in hybrid has a comprehensive system torque of 800N·m and a maximum system power of 385kW under the P2 single-motor PHEV structure.
Obviously, there is a certain degree of "mismatch" between the power and torque of the Mercedes-Benz pure electric G-class off-road vehicle. If you apply the era of fuel vehicles, everyone is more familiar with the saying. This trade-off of Mercedes-Benz is more like obtaining the effect of "low turn and high torque".
After entering the era of electrification, power, torque, and speed, among the three elements of the traditional engine, the most mentioned has become the speed. Under certain conditions, the speed and power are proportional, so the two are basically in a bound state. In the end, torque is more forgotten because of the characteristics of the motor's output, which allows the maximum torque output to be obtained in the early stages. As a result, no one is entangled anymore, as the speed of the motor climbs, its torque will decrease inversely proportional to the speed.
The reason for this gap in thinking is also very simple. Traditionally, torque is all that is needed to help the vehicle move. No one is going to hold back a low gear and drive normally in the rev range where the torque is dominant. In the era of electric motors without gearboxes, high speed has become the law to break through the top speed. But if we think about it carefully, hardcore off-road is not that "abnormal driving condition". As a result, in a wider range of working conditions, it is a priority to adapt to greater torque, which has become a performance issue for Mercedes-Benz pure electric G-class off-road vehicles. The idea of starting only from off-road working conditions, and not blindly following the common practices of the new energy era, may be the self-confidence of the "G-class" to occupy the spire of hard-core off-road vehicles for a long time.
But the problem is, the Mercedes-Benz pure electric G-class off-road vehicle really doesn't need high-speed working conditions? The solution is still very simple, a whole set of gearboxes. This operation has been applied to Porsche and Audi. The technical logic is completely inherited from the fuel vehicle. In the context of the motor completely ignoring the high speed of the wind, the efficiency loss of the two-speed structure is not worth mentioning compared to the high-efficiency range it can cover. The new problem is space, and if the front axle is completely free of the internal combustion engine to grab the position, it is quite easy. Then the space pressure on the rear axle is undoubtedly greater. To overcome this problem, pressure is put on the suspension.
Take out the chassis inventory, can the four motors and the body rigidity be both?
From the perspective of ordinary passenger cars, we have also talked about the rear suspension of pure electric vehicles many times. The high-power rear axle motor is destined to only match the standard five-link or H-arm multi-link. To put it simply, it is a derivative and upgraded version of the standard double wishbone suspension on the rear axle. In this way, the support of the vehicle can be ensured, and enough space can be freed up for the layout of the motor.
However, the hardcore off-road vehicle also faces a new problem, which is the contradiction between the traditional rigid connection between the rear axle and the rear motor. The easiest way to do this, of course, is to omit the rigid monolithic axle rear suspension. The thick swing arm and the new actuator hardware such as air suspension undoubtedly add a lot of color to the hardcore off-road vehicles in the new energy era. The above is also the routine operation of China's hardcore off-road vehicles. But for the Mercedes-Benz pure electric G-class off-road vehicle with "historical baggage", it is obvious that it still wants to "struggle" with the problem of the rear axle.
The Mercedes-Benz pure electric G-class off-road vehicle still adopts a rigid rear axle similar to the overall axle design, which guarantees the image of a hard-core off-road vehicle with a hard axle and a hard horse to the greatest extent. But a transverse shaft runs through the chassis, apparently sweeping away the place that would have been left for the motor. For this purpose, Mercedes-Benz's approach is to adopt a De Dion-style suspension structure. The Smart Fortwo, which used to be also owned by Mercedes-Benz, replicated the suspension structure. Essentially, this is a suspension design that addresses the relationship between the powertrain and the rear axle. It's just that after the towing arm form matured, the structure disappeared from the traditional passenger car.
Returning to the hardcore off-road vehicles of the new energy era, the De Dion-style suspension structure splits the hard axle from the driveshaft. By optimizing the position of the hard bridge, space is freed up for the placement of the motors. Then through the double universal joint drive shaft, the power is transmitted to the rear wheels on both sides. In the end, it not only ensures the overall rigidity of the vehicle, but also accommodates the dual motors on the rear axle, and at the same time strives for more travel space for the rear wheels on both sides.
In the end, the most attractive thing about this 3.5-ton big guy is the body rigidity and unparalleled agility that has been inherited all the way. It sounds like these two points are a bit of a conflict. But don't ignore the output of the motor, which is always crushed for the internal combustion engine. Under the torque tuning design of the Mercedes-Benz pure electric G-class off-road vehicle, the high-intensity off-road agility of the new car at low speed is almost at the ceiling level. Judging from the actual performance, the Mercedes-Benz pure electric G-class off-road vehicle can achieve 90-degree steering in situ in 1 second at the earliest. It can achieve a 360-degree rotation in 4 seconds, and supports up to two consecutive rotations at a time.
With the blessing of the four-wheel motor, it is not surprising to do the above action. The strength of the Mercedes-Benz pure electric G-Class off-road vehicle lies in the speed and frequency of the above actions. Of course, in order to do this, the Mercedes-Benz all-electric G-Class off-road vehicle has a two-speed gearbox and a clever design on the rear axle. It is still necessary to sacrifice its ultimate speed to a certain extent, as well as the loading capacity of the trunk. For example, the new car accelerates from zero to 100 in 4.7 seconds, but its top speed is only 180 km/h. Compared with the same level of fuel vehicles, or the same type of Chinese hard-core off-road vehicles, they are at a slight disadvantage. However, only considering the extreme off-road working conditions, if China's hard-core off-road vehicles think about the question of whether they can do it, then the Mercedes-Benz pure electric G-class off-road vehicle has made targeted technical preparations for the continuous high-intensity medium and low-speed off-road environment.