Mercedes-Benz S-Class is definitely one of the most concerned cars in China. From small to large, the three-digit chrome-plated number at the end of the S-class is the best representative to distinguish the class order, and the domineering symbols such as V8 and V 12, which represent the engine shape, are even more indispensable.
(Image from: adcarcare)
At this year's Shanghai Auto Show, Mercedes-Benz launched a new S-class small modified model in China, the world's largest luxury car market. The appearance has not changed much, but the engine has changed dramatically: the original V-shaped 8-cylinder engine of the new S400 has been changed into an in-line 6-cylinder engine.
Looking at the parameters carefully, the specific displacement of this inline 6-cylinder engine is 2925cc. At the beginning of this century, such an engine can only be awarded the title of S290. Now how does such an engine "regress" in the number of cylinders, displacement and engine shape and become the heart of the S-class sales benchmark S400?
48V electric system upper body, lighting hybrid system to improve power performance.
With the increasingly stringent global emission standards, there are three development trends of automobile engines as a whole: small displacement, turbocharging and hybrid power. The 48V electrical system used in Mercedes-Benz inline six-cylinder engine (hereinafter referred to as "Zhi 6") draws on the advantages of the above three technologies.
As we all know, the current electrical system of automobiles uses 12V voltage. However, with the increase of automobile electrical equipment and the emergence of hybrid power demand, 12V system is becoming more and more inadequate. For a simple example, if you drive a car with an automatic start-stop system, when you wait for a red light in summer, you will find that the engine will restart immediately after the car is turned off for a short time, because the electrical system of 12V can't withstand the air conditioning compressor.
However, under the current technical ability, switching to 48V electrical system is the best choice. 60V is a voltage standard that may cause harm to human body. The charging voltage of 48V system has reached 56V, which is the highest value without additional protection device.
After the vehicle is switched to the 48V system, on the one hand, the output power of the electrical system is greater, giving the vehicle more electronic equipment, and the possibility that the electronic control system can participate in the vehicle power output. On the other hand, the new electrical system also means the upgrade of new electrical structure and software capability, which improves the intelligent interconnection level of vehicles.
The 48V electrical solution of Continenttal, a famous automobile supplier.
According to the data released by Delphi, a well-known supplier of automobile electrical appliances, the light mixing system composed of 48V electrical system and traditional gasoline engine can achieve 70% energy saving effect at the cost of 30% of the current oil-electric mixing system, which saves about 15% more fuel than a single gasoline engine.
Specifically, the introduction of 48V electrical system plays five important roles in the new S-class straight 6 engine (code M256) of Mercedes-Benz.
The first is an electric turbine. In addition to the traditional turbine, the engine is also equipped with an electric turbine, which can be accelerated to 70,000 rpm by electric energy in 0.3 seconds. Before the traditional turbine came into play, the engine power increased, and the output instability caused by the hysteresis of the traditional turbine became history.
The second is power output. The motor can assist the power output. The most important thing is to keep the engine in a good working range and reduce the fuel consumption of the engine when the power increases.
The third is kinetic energy recovery. When the vehicle is in braking and deceleration state, the battery will store energy, and when the vehicle is in low-speed deceleration or cruising state, the system will turn off the engine and continue to save energy by using electric energy output.
Fourth, control more electrical equipment, such as water pumps, air compressors and other traditional equipment that need engine drive to be fully electrified, so as to reduce engine load and unnecessary start-up time.
Fifth, reduce the volume of the engine. After a large number of equipment were electrified, the belt, chain and other power transmission mechanisms on the original engine were removed, which greatly reduced the weight of this engine. The volume of the straight 6 engine is controlled within the length of the traditional straight 4 model.
In short, this is a powerful engine with greatly improved technical content and performance.
Adopt in-line 6-cylinder layout, modular or active machine.
Having said that, I still can't solve everyone's initial doubts: Why did Mercedes-Benz start to make a straight 6 engine again?
Although there are still different views on the advantages and disadvantages of Straight 6 and V6 in the industry, we can confirm a historical context: the earliest six-cylinder engine adopted in-line layout and then turned to V-shaped layout.
The inherent problem of in-line six-cylinder engine is that it is too large, and six parallel cylinders often fill the engine compartment. If you have paid attention to the classic cars in film and television works, the long engine part is not artistic, but a last resort.
On the other hand, after the cylinders of V6 engine are arranged in three dimensions, the overall volume of the engine is greatly reduced, making the spare space of the car body more spacious. At the same time, after the empty space in the engine compartment becomes smaller, it also provides more longitudinal buffer areas for collision, which improves the safety of vehicles.
It is one of the few BMW manufacturers that adhere to the straight 6 engine (image from: BlogSpot)
Although V6 engine still has some problems such as poor ride comfort, complex structure and high cost, for luxury cars, larger displacement and larger air gap are king, so V-engine has become the standard of high-end models. Except for BMW and Volvo, which still insist on straight 6/ straight 5 engines, other brands of high-end models have turned to the V-shaped camp.
V6 structure saves volume, but requires high materials and manufacturing technology.
However, more and more stringent environmental protection requirements have pulled automobile manufacturers back from the road of no return in pursuit of large displacement. In terms of environmental protection, the most stringent requirement of the European Union is that the carbon dioxide content of vehicles per kilometer should not exceed 95g in 2020, and the standard of China also reached 1 17g in the same year, requiring that the fuel consumption of vehicles should be controlled at about 4 liters per 100 kilometers. Small displacement turbine engines, such as the popular 2.0T series, will become the most important models.
Another knowledge is that the engine is modular. Modular design helps * * * enjoy producing parts and sharing R&; D cost, improve the adaptability of power system and reduce the cost of engine quality inspection.
Volvo's Drive-E series engines will meet the power needs of all models (image from: autokopen).
So, we saw BMW B series, Volvo Drive-E series and Jaguar Land Rover Ingenium series modular engines. Now, Mercedes-Benz will establish its own "Lego" kingdom.
At present, the mainstream engine is a combination of 3/4/6 cylinders. If the 4-cylinder is the main model for further research and development, the Zhi 6 is undoubtedly a more general model. At the same time, the cost of cylinder head, camshaft, valve timing system, etc. Lower, can save a lot of costs.
Modular engine can save considerable test cost.
So Mercedes-Benz changed the straight 6 engine this time, probably to save money, and it is a lot of money.
A small step in engine model will affect a big step in the next decade.
Now mentioning Straight 6 will arouse the inexplicable pride of BMW fans, but in fact Mercedes-Benz has occupied a place in this club.
Mercedes-Benz 190EAMG (image from: autodor)
In the 1980s and 1990s, the mid-range models of Mercedes-Benz's high-end series always used inline 6-cylinder engines. 1984, 190EAMG is the first Mercedes-Benz model with a straight 6 engine. In that seemingly stable Mercedes-Benz era, the same conventional straight 6 engine also operated under the hood.
Mercedes benz C36AMG (Image from: autodor)
Since 1995 C36AMG, the V-engine has been playing the leading role on the big stage of Mercedes-Benz, and it has continued to this day. It can be seen that every time the engine system is updated, it will maintain a long life cycle.
We can boldly infer that the updated straight -6 engine system is likely to support the engine application requirements of Mercedes-Benz luxury car series in the next decade, and even support the day when pure electric vehicles become mainstream. In the future S-class, it is likely that the straight 4 engine will be an entry-level model, the straight 6 engine will occupy the middle end, and the straight 6 hybrid engine will sit firmly at the high end.
Million car purchase subsidy