New Mercedes-Benz 1.8L Petrol Engine with 238hp and 400Nm!

With moderate disappointment over the upcoming W204 C-Class range of engines, especially with regards to carrying over the M271 Kompressor powerplants largely unchanged, the DiesOtto engine developments will be much rejoiced by Mercedes-Benz fans the world over. After all, who doesn’t want power, economy and environmental friendliness all in one package? In Malaysia, an added bonus to this development is the annual road tax of a 1.8L engine!

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From the image, the DiesOtto engine still looks pretty much like the all-aluminium M271 in external architecture. What this means is that the motor could possibly be fitted easily to all Mercedes-Benz vehicles planted currently with an M271 engine. To sum it up, the DiesOtto is capable of 238hp and 400Nm while returning a respectable fuel consumption of just 6L/100km. How soon will this powerplant make it into the engine bays of W204 (perhaps the facelift model?) and/or the all-new W212 E-Class remains to be seen. Let’s just hope that this technological update announcement by Mercedes-Benz does not remain just a media release, like all its previously announced plans of full range GDI engines for the W211 E-Class and Turbocharging +GDI motors for the W204 C-Class. Only then can future M-B owners relish the powerplant technological advancements of their favourite rides, against the Munich or Ingolstadt counterparts.

Mercedes-Benz DiesOtto powerplant key technological features are as follows:

1) Downsizing with fewer cylinders and a smaller displacement
2) Turbocharging for superior performance
3) Direct gasoline injection as a further fuel economy measure
4) Controlled auto ignition, a combustion process similar to that of a diesel
5) Variable valve control
6) A variable compression ratio leading to even better fuel economy
7) A hybrid module with an integrated starter/generator, which makes the drive unit even more economical (optional)

Press release as below:

Mercedes-Benz DiesOtto – a further development of the spark-ignition engine

Mercedes-Benz has combined all the advantages of both engine types in its DiesOtto powertrain. The performance of a gasoline engine, the high torque and fuel economy of a state-of-the-art turbodiesel together with extremely clean emissions is now possible. The new technology package, which stands for the future of the petrol engine, includes features such as direct gasoline injection, turbocharging and a variable compression. At the core of this innovation lies the controlled auto ignition, a highly efficient combustion process similar to that of a diesel. By way of another advantage, and in contrast to comparable developments, the Mercedes system requires no synthetic fuels but can be operated using conventional petrol.

Optimising the internal combustion engine is one of the milestones on the Mercedes-Benz roadmap for sustainable mobility. BLUETEC has already made it possible for Mercedes engineers to make the powerful and economical diesel as clean as the gasoline engine. In the US, this technology has already been available in the E-Class since 2006, and it will also become available in Europe from the end of this year. The W211 E300 BLUETEC will be by far the cleanest diesel in its class, and will meet the requirements of the EU5 exhaust emission standards in full.

"Our next goal will now be to make the gasoline engine as economical as a diesel. All the preconditions for this are provided by our DiesOtto concept, which incorporates the foremost strengths of both the gasoline engine and diesel engine," says Prof. Dr. Herbert Kohler, Head of Group Research & Advanced Engineering Vehicle and Powertrain; Chief Environmental Officer of DaimlerChrysler.

The result of this “marriage" is a four-cylinder unit with a displacement of just 1.8 litres, which combines the strengths of the low-emission gasoline engine with the fuel economy of a diesel. Despite its considerably reduced displacement – downsizing is one of the major factors for achieving lower fuel consumption – this compact power unit delivers superior performance together with refinement at the level of the luxury class. An output of 175 kW/238 hp and a maximum torque of 400 newton metres are achieved together with the hybridisation a fuel consumption of less than 6L/100 kilometres! This fuel economy figure by no means relates to a small or compact car, but to a vehicle the size of the current S-Class, with the level of comfort and safety that is typical of a Mercedes-Benz.

“In line with the worldwide success of today's diesel engine, vehicles equipped with gasoline engines will continue to have a long-term attraction for many customers and in many markets. Accordingly we are giving our attention to both engine types – including a full hybrid option for diesel and gasoline vehicles, " says Prof. Kohler. Mercedes-Benz is working on its DiesOtto concept with corresponding emphasis.

When starting and under full load, the fuel/air mixture is ignited by a spark plug, as in a conventional spark-ignition engine (homogeneous combustion). The controlled auto ignition to which the DiesOtto automatically reverts within its working cycle occurs under partial load conditions, i.e. at low and medium engine speeds.

The result is the very low nitrogen oxide emissions of homogeneous combustion at reduced reaction temperatures. All further emissions control in the DiesOtto engine is by means of a standard three-way catalytic converter. A highly efficient engine management and control system has also been realised to combine the individual sub-systems into a drive concept.

The current prospects for the future of the internal combustion engine reveal its great potential, and show that the new drive concept is a feasible proposition in the mid-term. Some of the intermediate solutions incorporated, e.g. direct gasoline injection, are already in series production at Mercedes-Benz. Others will be gradually integrated into series-production engines until the overall solution has been realised.