Sports Utility Vehicles (SUVs) have been dominating the roads since 1990 when Ford found this panacea for the ailing U.S. auto industry. Currently, SUVs, minivans, and pickups account for 50 percent of auto purchases in the United States. But what has been good for automakers may not be as good for the ozone layer.

Not only do SUVs look like trucks, they pollute like trucks. SUVs are freed from fuel emissions standards that most cars have to meet. Minivans and SUVs spew 30 percent more carbon monoxide and hydrocarbons and 75 percent more nitrogen oxides in the air than passenger cars. They also guzzle gasoline. The new super-size Ford Excursion, for example, gets about 12 miles per gallon. As a result, overall fuel economy for all passenger vehicles is at its lowest since 1980.

Although there has been some movement to decrease emissions, the Clinton signed a $50 billion transportation spending bill banning any federal increase in fuel economy requirements for SUVs. So auto manufacturers are riding high, with fuel economy requirements of 20.7 miles per gallon for most SUVs, compared to 27.5 mpg for cars. Should that loophole be closed?

On One Hand...

Car manufacturers, hungry for profits, don't care much about the environment. These fuel-mongering vehicles are accelerating the depletion of the ozone layer. They also create ground-level ozone, which causes asthma and lung damage. Cars account for 20 percent of the CO2 emissions in the United States. Meanwhile, the technology to cut this back by increasing SUV fuel efficiency to 34 miles per gallon already exists. It is reasonable and technically feasible to require SUVs to meet a more efficient fuel use standard.

On the Other Hand...

SUVs don't really have that much of an effect on the environment. Emissions from new vehicles only cause about two percent of U.S. carbon dioxide emissions. As polluters go, SUVs are minor offenders when compared to jets, diesel trucks, and buses. To reduce tailpipe emissions, automakers will almost certainly have to lighten up SUVs considerably, making them less safe. Studies by the National Highway Transportation Safety Board show that every 100-pound reduction in weight for passenger vehicles leads to an estimated 10,000 more incapacitating injuries in traffic accidents.

• The new Ford Excursion is 19 feet long, 6 1/2 feet wide, 8,500 pounds, and averages 12 miles per gallon on the road. Because it is so heavy, it is not subject to the "light truck" emissions standards that apply to most SUVs.

• The combined average fuel efficiency of all vehicles on U.S. roads went from 25 miles per gallon in 1985 to current rate of 24.5 mpg.

• An EPA proposal specifies nationwide tailpipe emission standards similar to those already adopted for 2004 by California, which requires vehicle fleets to reduce emissions of smog-causing chemicals by almost 90 percent from those of today's vehicles. It would require that SUVs meet essentially the same emissions caps as cars, although they would be given two additional years of phase-in time. President Clinton has endorsed proposals that would require all SUVs to meet emissions standards for cars by 2009.

• Last year President Clinton signed a $50 billion transportation spending bill that specifically bars changes in federal fuel economy requirements.

• According to the Sierra Club, the least costly step the nation could take to curb the "greenhouse effect" would be to toughen fuel economy standards. Vehicles subject to these standards accound for 20 percent of CO2 emissions in the United States.

• In a recent speech to stockholders, Bill Ford spoke about the environmental drawbacks of SUVs. While admitting that the SUVs were too profitable to give up, he promised that Ford would use its profits to look for new technologies that would make the SUV "cleaner and greener."

Money, Sierra Club, Associated Press