Their timing was good. Earlier that day, US President Barack H. Obama announced more stringent motor fuel efficiency standards. So the automobile and diesel engine manufacturers at the Diesel Technology Forum’s late afternoon reception on May 19 were feeling optimistic.“People are warming up to the idea that no single technology is going to solve the climate challenge. The economic slowdown is also making them conserve, and diesel fuel fits the bill. The engine is very clean and efficient. It does not require new infrastructure. Diesel is already sold at 42% of the nation’s gasoline stations,” explained Allen R. Schaeffer, the forum’s executive director.&ldqu...