The Clinton-Gore Administration proposed significant reductions in tailpipe emissions from cars, light trucks, and SUVs, and heavy-duty trucks and buses. These represent the toughest standards ever for reducing harmful air pollution from auto tailpipes - an action to make new cars 77 to 95 percent cleaner than previous standards. The effect of the rule removes 50 million tons of smog-causing air pollution over the coming decades. In addition, the Administration's rule on clean diesel fuel requires that diesel contain less sulfur and run in cleaner engines when it goes into effect in 2006-2007.