Comparison of hybrid technology between Lexus LS600hL and Mercedes-Benz S400 Hybrid

    When people still habitually believe that cars that save the earth should be small in size and weigh no more than 1.2 tons, high-end luxury car manufacturers are doing the opposite, combining large displacement with hybrid technology. Such development is not a unreasonable response, but many people just didn't expect it.

    Compared with Japanese automakers, European brands did start late in hybrid technology. And the manufacturing concepts of Mercedes-Benz and BMW's hybrid cars are not exactly the same as Lexus'.

 

    Although the LS600hL does not use the top V12 engine, the power level of the V8 engine has been greatly improved through the hybrid system, which can be said to be the culmination of Toyota's hybrid technology. In addition, in order to take into account fuel economy, it also abandoned the 8-speed automatic transmission and switched to a special CVT transmission. The Mercedes-Benz S-Class has long been the overlord of this level, so the identity of the S400 Hybrid is the stepping stone for Mercedes-Benz to enter the hybrid field. It does not carry too much business mission, nor does it need to achieve the performance of a 12-cylinder sedan, as long as it is fuel-efficient. Therefore, Mercedes-Benz wisely chose the "moderate hybrid" form, and its hybrid module is only an auxiliary system of the internal combustion engine and participates in work all the time. The system has two main functions. One is to provide additional driving force during acceleration; the other is to recover energy during braking and store kinetic energy as electrical energy.

 

Hybrid technology of the brand

 

    However, such a simple and slightly similar hybrid module brings excellent fuel economy to these three cars. In the European NEDC test, the S400 Hybrid's fuel consumption per 100 kilometers is only 8.0L, which is about 20% less than the S350 with the same engine. The fuel consumption in actual use is usually higher than the ideal value, but even so, the actual driving still obtained a measured value of 11.2L/100km, which is a good result even for some mid-size cars. At the same time, the measured fuel consumption of Lexus reached 13L/100km, which is a little higher than we expected.

 

    Of course, we can't conclude that Lexus is inefficient. The Mercedes-Benz S350 is equipped with a 3.5L V6 engine, while the LS600hL is equipped with a 5.0L V8 engine. It is not easy to achieve such a fuel consumption level. If the scope of activities is limited to the city, the Lexus may have a more gratifying performance, because although both cars can automatically shut down the engine when slowing down or stopping at red lights, the Lexus has an additional important function - running completely on electricity. The nickel-cadmium battery pack can only support it to travel about 1km when fully charged, but if it is used entirely on stop-and-go city roads, it can obviously play a very positive role in reducing pollutant emissions.

 

    Lexus' hybrid system is the most complex and large of the two cars, and it is equipped with so many on-board comfort equipment that it weighs an astonishing 2410kg. It is not only 240kg heavier than the pure gasoline version of the LS460L, but also more than 200kg higher than the Mercedes-Benz S400 Hybrid and BMW 740Li hybrid. All of this will be directly reflected in fuel consumption.

 

    In contrast, Mercedes-Benz's pragmatic approach is more practical. Since there is no need to drive the vehicle alone, the battery capacity does not need to be large, and lithium-ion batteries with higher energy density are used, reducing the weight of the entire system to about 75kg. Its battery pack is only slightly larger than an ordinary car battery and can be installed directly in the engine compartment, rather than placing the battery pack in the trunk like Lexus, sacrificing almost half of the luggage space. More importantly, this system is compact and fully modular. In theory, it can be applied to any Mercedes-Benz product with only a slight modification, and the manufacturing cost and difficulty can be greatly reduced. In fact, the price of the S400 Hybrid is a good proof of this. It is only 60,000 yuan more expensive than the standard S350, while the price difference between the LS600hLL and the LS460L is 500,000 yuan.

 

Driving experience

 

    So how big is the difference in driving these two cars? This is probably a matter of details. Sitting in front of the steering wheel with a relaxed attitude, their throttle response is lazier than the corresponding standard version, or a little too cautious to avoid wasting fuel. The difference is that the Mercedes-Benz achieves it through the "low speed and high gear" method, while the Lexus rarely lets the engine participate in the work when starting, and basically automatically intervenes after the speed reaches 20km/h, and before that it is so quiet that you can hardly hear any sound.

 

    If you treat the accelerator pedal roughly, Lexus will cooperate very well, and the engine will be awakened quickly, releasing more powerful power. When the engine and motor work synchronously, the system power of this car is as high as 327kW, and it only takes 6.4 seconds to accelerate from standstill to 100km/h. In the same situation, Mercedes-Benz will hesitate a little, because it has to jump out of the economic mode, downshift to a suitable low gear, and then exert force and jump out suddenly. Obviously, Mercedes-Benz's engine displacement is slightly inferior, and the motor power is only 1/10 of Lexus, so its 0-100km/h acceleration time is a slightly slower 7.2s.

 

    The engine of the 2013 BMW 740Li hybrid model has been replaced by a 3.0L inline 6-cylinder single-turbocharged engine instead of the 4.4L twin-turbocharged V8 engine of the old hybrid model. It should be noted that this engine is also installed in the regular version of the new 740Li. In addition, the maximum power of the new car's electric motor is 41kW and the maximum torque is 210Nm. The maximum power of this motor is 26kW higher than that of the old model. After combining the two, compared with the regular version of the 740, the new car's maximum power will reach 260kW, the maximum torque will reach 500Nm, and the acceleration from 0 to 100km/h will be 5.7s. However, the fuel consumption has been reduced by 11%. In terms of transmission, the new 740Li hybrid has an 8-speed automatic transmission instead of the 6-speed automatic transmission of the old model.

 

    In terms of battery pack, the BMW 740Li hybrid uses the lithium-ion battery pack installed in the old model. It is arranged in a closed space between the rear seat backrest and the trunk. The capacity of the battery pack is 90Ah, the same as that of the old hybrid model. In pure electric driving mode, the vehicle can travel up to 4km with the power of the battery pack and the maximum speed can be 60km/h. In addition, the ECO PRO energy-saving mode (with inertial gliding mode) of the BMW 740Li hybrid model ensures the most efficient collection and utilization of all available energy. In ECO PRO mode, the throttle response will become slower, thereby saving corresponding fuel.