Detroit

WHEN TREASURY SECRETARY John Snow announced guidelines for a new tax cut for the rich here last week, liberals did not denounce him. That’s because the proposed tax breaks were for gasoline-electric hybrid vehicles, the favorite ride of environmentalists this side of bicycles. But the dirty secret about hybrids is that, even as the government continues to fuel their growth with tax subsidies, they don’t deliver the gas savings they promise.

Most cars and trucks don’t achieve the gas mileage they advertise, according to Consumer Reports. But hybrids do a far worse job than conventional vehicles in meeting their Environmental Protection Agency fuel economy ratings, especially in city driving.