Petrol donk, diesel genes

MERCEDES-BENZ claims to have combined the advantages of both petrol and diesel engines – including low emissions of the former and high torque and fuel economy of the latter – with its “DiesOtto” powertrain concept unveiled last week.

“Otto” translates to “petrol” from German to English. The 1.8-litre four-cylinder petrol engine has direct-injection, turbocharging, variable valve control and a variable compression ratio, along with a diesel-oriented “controlled auto ignition” combustion process.

The latter works at low and medium engine speeds, while the conventional spark ignition occurs at start-up and under full load. The small displacement is needed to reduce consumption, but the output is an impressive 175kW of power and 400Nm of torque.

Economy is claimed to be less than 6.0L/100km for a vehicle the size (and specification of) the S-class.

“Our next (production) 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,” said DaimlerChrysler’s head of group research and advanced engineering (vehicle and powertrain) Herbert Kohler.