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Registered '07 SLK55
806 Posts
Discussion Starter #1
Mercedes Benz's new "DiesOtto" engine. Combining the cleanliness of gasoline engines with the high torque and efficiency of a diesel.

Engine Specs: 1.8L Turbocharged 4 Cylinder
Horsepower: 238bhp
Torque: 295lb/ft
MPG: Approximately 40mpg in a vehicle the size and weight of an S class
Fuel: Regular Gasoline

And the Articles: said:
STUTTGART, Germany — Mercedes-Benz rolled out the intriguing DiesOtto powertrain concept on Tuesday. It's basically a cross between a gas and a diesel engine that "requires no synthetic fuels but can be operated using conventional gasoline." It did not specify a timetable for when such a unit would be available in a production vehicle, stating only that "the new drive concept is a feasible proposition in the midterm."
"Our next goal will now be to make the gasoline engine as economical as a diesel," said Herbert Kohler, Mercedes-Benz head of group research and advanced engineering vehicle and powertrain and DaimlerChrysler's chief environmental officer.
The DiesOtto is a 238-horsepower 1.8-liter four-cylinder engine that delivers 295 pound-feet of torque. It features direct gasoline injection, turbocharging and variable compression, along with "controlled auto ignition," which is described as a "highly efficient combustion process similar to that of a diesel." Fuel consumption is said to be "less than 6 liters of gasoline per 100 kilometers," or about 39 mpg. Mercedes-Benz said the aforementioned numbers do not apply to a "small or compact car, but to a vehicle the size of the current S-Class."
Kohler added that with the market enthusiasm for diesels and conventional gas engines, the automaker is "giving our attention to both engine types — including a full hybrid option for diesel and gasoline vehicles."
What this means to you: Sounds like a winning combination! You get the benefits of a diesel without having to search out a filling station with diesel fuel.
Automotive News said:
Mercedes-Benz is preparing to display several new frugal drivetrain concepts at September’s Frankfurt Motor Show, the latest being a new ‘DiesOtto’ engine that will be revealed for the first time later this month.
The new engine features engine concepts that characterize both diesel and petrol motors, and promises to be as clean as petrol engines but as efficient as diesels.
The technology is similar to Volkswagen’s recently announced Gasoline Compression Ignition system, which works by using spark plugs during start-up and hard acceleration, while relying on sparkless compression ignition, like a diesel, during low load situations.
In an interview with Automotive News, a Mercedes official explained that VW’s technology is still several years away because it requires a special synthetic fuel that’s still in development, while the Mercedes will run on regular petrol.
ABF said:
1.8 Liters, 240bhp, 295 lb/ft and 40mpg in a vehicle as heavy as an S-class. According to Mercedes, this is the future of gasoline engines. Featuring direct injection, a turbocharger, variable compression and a hybridized starter motor, the DiesOtto engine would be impressive with these features alone. The real innovation, however, is the controlled auto ignition, a combustion process similar to that of a diesel engine. No word yet on when it goes into production or in which vehicles it'll be used. Full press release after the jump.
Stuttgart - The performance of a gasoline engine, the high torque and fuel economy of a state-of-the-art diesel together with extremely clean emissions: Mercedes-Benz has combined all the advantages of both engine types in its DiesOtto powertrain. The new technology package, which stands for the future of the gasoline 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 gasoline. 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 E 300 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 a 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 six litres of gasoline per 100 kilometres. This 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. Mercedes-Benz DiesOtto - a further development of the spark-ignition engine " 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. Its key technological features are as follows:
* Downsizing with fewer cylinders and a smaller displacement
* Turbocharging for superior performance
* Direct gasoline injection as a further fuel economy measure
* Controlled auto ignition, a combustion process similar to that of a diesel
* Variable valve control
* A variable compression ratio leading to even better fuel economy and, depending on customer needs and the type of operation,
* A hybrid module with an integrated starter/generator, which makes the drive unit even more economical.
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.

Founding Member
4,599 Posts
Why only the S-class??? I think it'll be great for all the models. Imagine a 40mpg plus SLK, that'll be awesome, thanks for sharing, MB is really is the leader in technology.

Founding Member #2 2008 SLK55 AMG
19,407 Posts
Thanks Mark for the article. I wouldn't mind an SLK 180 with 400NM of torque.

Premium Member 2006 SLK55 AMG
3,055 Posts
It's not the S class only, it's just that calculations are based on an S class. the same engine in an SLK should be far more effiecient. They mention the S class because a lot of other manufactures estimate engine efficiency using their smallest, lightest, and most aerodynamic cars (without mentioning it) to give the impression of how efficient the engine is.

'short term' for manufacturers usually mean 1-3 years, 'long term' being 15+ 'midterm' is what, 10 years away?
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