Petrol-driven engines can be greener than you think, claims Mercedes-Benz, which has combined the performance of a petrol engine, and the high torque and fuel economy of a diesel engine, together with “extremely clean emissions” in its new DiesOtto powertrain.

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The company claims that the DiesOtto has a fuel consumption of less than six litres of petrol for every 100 kilometers and has an output of 238 horsepower. It also includes features such as direct petrol injection, turbocharging, and variable compression. The engine also has a highly combustion process similar to that of a diesel but can be operated using conventional petrol.

Mercedes-Benz Head of Group Research & Advanced Engineering Vehicle and Powertrain, Dr. Herbert Kohler said, “Our next goal will now be to make the petrol 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 petrol engine and diesel engine. In line with the worldwide success of today’s diesel engine, vehicles equipped with petrol 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 petrol vehicles.”

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 petrol 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

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 are already in series production at Mercedes-Benz. Others will be gradually integrated into series-production engines soon.