I wrote a post about Shuangqing power earlier, and everyone was very interested in it, so let’s continue writing about Shuangqing’s unique four-wheel drive this time! Let me start with my personal opinion: For SUVs with cracked walls, it is recommended to buy a four-wheel drive model. The reason is simple: even the lowest four-wheel drive SUV has much better passability than a two-wheel drive SUV. There is an essential gap between the two!
First of all, the dual-engine four-wheel drive structure (e-four) is very unique and completely different from other models: the structure is very simple, with a 40kw rear motor + open differential forming the rear axle drive system.
Compared with traditional four-wheel drive SUVs: heavy transmission shaft + coupling four-wheel drive structure, the dual-engine e-four has the advantages of small size, light weight, flexible layout, and another important advantage : The power output of the front and rear axles can be completely independently controlled, and the reaction speed of the rear axle motor is faster than any mechanical device.
This is the core technology of Shuangqing: the power control unit pcu (Power Control Unit), which is a key component to realize electric four-wheel drive. One of its important functions is to control the power of the generator or battery. The 201.6v voltage is converted into the 650v high voltage required for the front and rear drive motors. Due to the loss of electric energy conversion and the amount of heat generated, a cooling system is specially equipped.
Many car enthusiasts think that e-four is just adding a motor to the rear axle. It seems very simple but actually involves extremely complex control logic of the PCU. Starting from 2016, many Toyota hybrid technology patents have expired one after another. Some media once slapped their heads and boasted: Toyota hybrid will be besieged... What is the actual result? All seriously underestimate the technical content of the four-wheel drive PCU control logic. Even though Honda can build airplanes, it still has no commercialized mature solution. The technical difficulty can be imagined!
I’ve written too much about technology, and I’m afraid that car enthusiasts will get a headache from reading it. In short: the Rav4 dual-engine e-four follows the very mature electric four-wheel drive technology of Lexus, and its reliability is beyond doubt. ! Its structure is simple, small in size and light in weight, and its fuel economy and four-wheel drive efficiency are very high!
****Let’s talk about the obvious benefits that dual-engine four-wheel drive can bring to everyone...
First of all, dual-engine four-wheel drive The e-four has more 40kw motors than the two-wheel drive, and the driving force is significantly stronger. There is no doubt that it is much faster and more powerful than the two-wheel drive, whether starting or midway acceleration. This alone is a temptation for experienced drivers who are upgrading their vehicles. Full of power! (Tested on real cars, due to the large torque, the impact on acceleration from full load is minimal)
The fifth generation rav4 is a newly developed medium-sized ga-k platform. The dual-engine battery and motor transmission system are very compactly located on the rear axle. Nearby, this brings a more balanced body weight than the fuel rav4. Simply put: when the vehicle is on a bumpy road, the rear wheels will bounce less, which can improve comfort and control. (I used to drive a dual-engine Corolla and found that its shock absorption comfort is better than that of a fuel-powered Corolla)
Secondly, it is a commonplace topic: the dual-engine e-four can dynamically distribute power to the front and rear axles, which can be greatly improved. The vehicle's controllability, whether driving on urban curves or suddenly changing lanes at high speed, has significantly better body stability! Personally, I sneer at the idea that four-wheel drive is useless on urban roads. But as the saying goes: go for a test drive and you will be able to tell the difference in just one corner!
Some car enthusiasts hold on to old ideas and still cannot understand: Rav4 four-wheel drive can improve vehicle control. It is very simple: multi-function keys on the steering wheel - adjust left and right to vehicle information - select four up and down Drive status, check the displayed four-wheel drive status information while driving... Don't be ridiculous, as long as the four-wheel drive rav4 instrument has this function!
There is no doubt that the dual-engine e-four can greatly improve vehicle passability! Tackling slippery icy roads or muddy puddles is a breeze.
After turning on the trail next to the shift lever, the electronic braking to prevent slippage and idling will be stronger and can cope with complex roads with rugged terrain... I must remind you here: Don't expect to use it. The dual-engine e-four is a hard-core off-road vehicle. There is no comparison between the two in terms of body structure or four-wheel drive system!
The dual-engine e-four is more than 10,000 more expensive than the two-wheel drive dual-engine, but the benefits it brings are also very obvious: it is more powerful and accelerates faster; it can significantly improve the handling; and its off-road passability is also enhanced. Although you can’t expect to use it every second, it satisfies everyone’s self-driving travel without stress. At least you don’t have to rely on your fingers to predict the weather when going out in the northern winter.
Some time ago, Autohome tested the dual-engine rav4 and mentioned the problems of the e-four, allowing some keyboard enthusiasts to instantly find the opportunity to take the lead. Let me talk about my humble opinion: First of all, the above picture says that the battery is exhausted and it means that it is a front-wheel drive car. This is an obvious misjudgment. Because of the battery protection mechanism and generator, the battery capacity of hybrid vehicles will not be less than 30%, so it does not exist during use. Change two drives and one theory.
It is a fact that it cannot pass steep slopes at large angles. This is due to the dual-engine e-four structure: at large angles, the center of gravity of the vehicle shifts significantly rearward, and the front wheels have no power, but they cannot obtain enough friction, and most of the driving force is It is borne by the rear wheels. Obviously, the 40kW power of the rear axle is not enough to push the vehicle through.
****Note that the large angle here specifically refers to exceeding the normal maximum climbing angle of the vehicle, which is a very extreme situation. Therefore, I hope everyone can understand: the dual-engine e-four has no problem handling the steep slopes we encounter every day, but due to the electric four-wheel drive structure, the limit is indeed not as high as some SUVs with traditional structures.
As for some people complaining about the e-four: the power of the rear axle motor is too small and useless, and it is a typical keyboard driving. Let me give you some data: the rear axle motor power of the Prius AWD model is only 5.3kW and the torque is 55Nm. This power is enough to give it the ability to pass through ice and snow roads and improve control.
****It is enough. If fuel efficiency is affected in pursuit of the limit, it will obviously outweigh the gain!
It is true that the price difference between dual-engine four-wheel drive and two-wheel drive is more than 10,000 yuan. I personally think it is worth it! The extra money you spend can be exchanged for: three-motor configuration, stronger power performance; balanced front and rear weights of the body, better control and comfort; in terms of off-road passability, there is an insurmountable gap for two-wheel drive. It can be seen that although four-wheel drive and dual-engine are not 100% perfect, it still has an overwhelming advantage over two-wheel drive!
****One point needs to be reiterated here: Don’t think of off-roading when you mention four-wheel drive. SUVs are not equal to hardcore off-road vehicles. The body structures of the two are completely different. It can be seen from the development history of SUVs that on the basis of ensuring light off-road performance, greatly enhancing vehicle handling performance is the general trend in the future.