Automakers bragged more about fuel consumption and recycling than acceleration. Honda showed off its new Civic, which claims to get 55 miles per gallon in a relatively roomy car. Dominating the show were more than 20 prototypes of electric cars.

The search for new energy sources took Mercedes-Benz to rapeseed oil to power diesel engines. A spokesman boasted of its performance-and scent. “It smells a bit like french fries out of the exhaust pipe,” he said. Several German carmakers also announced that they will take back junked 1992 models for recycling, free of charge. It might sound like offering burial insurance at the maternity ward, but that’s the kind of pitch that could appeal to today’s garbage-wary consumers.