General Motors Tests Diesel-Like Powerplant To Meet Future Fuel Economy, Carbon Cuts
Exactly one day after President Obama announced a new plan to clean up gas-guzzlers and carbon emissions in the transportation sector, General Motors on May 20 said it is working to combine the advantages of gasoline and clean-diesel technology to meet those goals.
Tested so far on midsize cars and in the lab, GM says that homogeneous-charge compression ignition (HCCI) engines produce 15% greater fuel economy and equally less carbon using regular gasoline, without the expensive tailpipe scrubbers that today’s clean diesels require. The experimental motors use a spark to start cold but later switch to auto-ignition after warm-up, GM says. Traditional diesels, which are more fuel efficient than gasoline engines while producing more low-end torque, also use compression heat to ignite the air-fuel mixture.