Every vehicle that Mercedes-Benz releases comes with the usual attributes expected from the brand. This includes offering the best safety features, both passive and active. It should also have maximum ride comfort while ensuring a straightforward operation.
The vehicle should also be reliable with first-class workmanship using selected materials. All of these attributes combined mean that vehicles from Mercedes-Benz offer the best efficiency possible. The challenge however was to make sure that all of these are present in a hybrid car.
This is why when the engineers started working on the SUV with a hybrid drive, they made sure that even from the concept phase it had to have the attributes mentioned. Aside from the characteristics, the company’s drive system is also proof of its strength and use of leading technology.
In order to meet these objectives, the company would need to undergo a complete development cycle like developing a new model from scratch. Even before the Mercedes-Benz ML 450 HYBRID managed to arrive at series-production maturity, certain tests had to be done.
To determine for example if the system was indeed reliable, technicians and engineers had to run a total distance of four million kilometers. These involved different climatic conditions like the humid temperatures in the tropics, sub-zero temperatures of the Arctic Circle, and even the scorching heat of the desert regions.
This work was complemented using the "Digital Prototype" with its detailed simulations and wide-ranging test-rig program. While the ML 450 HYBRID was still being developed, the objective was to ensure that the different subsystems inside its powertrain match.
The importance of system matching is that the different drive modes can be used without difficulty even while the vehicle is being driven. The ML 450 HYBRID has a two-mode hybrid technology with a drive design that can operate using pure electricity, its combustion engine alone, or a combination of both.
This is all due to the fundamental work done by the "Global Hybrid Cooperation". This group is responsible for bringing together all of the research and development performed by different automakers like BMW Group, Chrysler, Daimler AG, and General Motors.
The two-mode hybrid technology exhibits a number of advantages. Fuel consumption and emission for instance have been lowered by as much as 60% yet the performance is similar to your standard all-wheel drive eight-cylinder SUV.
A version has been tailor-made for the U.S. market with a fuel consumption of 21 mpg 'city' and 21 mpg 'highway', figures that can be said as the most efficient in its class. Since this SUV has been classified as a Super Ultra Low Emission Vehicle, it meets even the strictest of emission standards in the U.S. that have been set for vehicles that use combustion engines.
The ML 450 HYBRID delivers 250 kW, around 340 hp, of power with 517 Nm of combined total torque. The result is a driving experience that is unmatched while the level of ride comfort is increased. Since the drive management system of the ML 450 HYBRID is completely automatic, the driver can focus on the road ahead without the need to choose any of the added functions.
Still, the permanent all-wheel drive 4MATIC system continues to retain its functions. At the core of this hybrid drive is the transmission unit that is composed of four clutches, three planetary gear sets, and two electric motors.
The configuration of the transmission allows the power to be transmitted to either an electrical path or a mechanical one. This is the advantage of a two-mode hybrid system as one-mode hybrid systems are unable to have any mechanical ratios.
Thus for one-mode hybrid systems, majority of the power is transmitted through the electrical path using a high electrical output and thereby lowering the efficiency.