Light Trucks And Dirty Air

Sport-utility vehicles have always been odd automotive beasts. Part miniature truck, part muscled-up car, they have all the amenities of a family sedan and all the gas-gulping bulk of a big rig. Now the SUV will have to do a little downsizing--at least when it comes to tailpipe emissions. Last week President Clinton announced new rules requiring SUVs and other so-called light trucks to put out no more pollution than an ordinary car.

Until now the Environmental Protection Agency has gone pretty easy on light trucks, allowing them to release between 0.7 gram and 1.5 grams of smog-producing nitrogen oxide per mile, in contrast to 0.3 gram for smaller vehicles. The problem is not just the size of trucks and cars, but also the fuel that powers them. Gasoline contains up to 300 parts per million of sulfur--more than enough to foul emission-control devices. Under the new rules, oil refiners must slash that figure to 30 p.p.m. At the same time, automakers must improve the way all vehicles digest fuel, building cars and SUVs that emit a bare 0.07 gram of nitrogen oxide per mile.

The changes won't come right away--the new rules will be phased in slowly between 2004 and 2009--and they won't come cheap. The EPA estimates that consumers will see a 1[cent]-to-2[cents] per gal. price jump at gas pumps and a $250 boost in the price of some SUVs, though oil companies warn that the fuel costs could be higher. But not too high to outweigh the benefit, say environmentalists. It's time, they contend, for a vehicle that walks like a truck and talks like a truck to begin breathing like a car.