Mercedes-Benz has announced that it has combined all the advantages of both petrol and diesel engines in its “DiesOtto” powertrain. Its potential is indicated by the prospect of a mild-hybrid-assisted 1.8-litre engine giving 47 mpg in a future S Class-size car. The new technology includes features such as direct gasoline injection, turbocharging and variable compression, but at the core of the innovation lies controlled auto ignition, a combustion process similar to that of a diesel. The Mercedes system can be operated using conventional gasoline.

Following Mercedes’ launch of the E300 BLUETEC Euro 5-rated diesel engine, already on the U.S. market and due in Europe from the end of this year, Prof. Dr. Herbert Kohler, Head of Group Research & Advanced Engineering Vehicle and Powertrain and Chief Environmental Officer of DaimlerChrysler says: “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.”

The first DiesOtto engine described in Mercedes’ release is a 1.8-litre four-cylinder unit with an output of 175 kW/238 hp and a maximum torque of 400 newton metres, and fuel consumption, with the accompaniment of a mild hybrid starter-alternator, of under 6 litres per 100 kilometres (47 mpg) in a car the size of the current S-Class.

Its key technological features are:

- 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.

Wow, maybe we can expect gasoline prices to go down… Sometime in a future.