The EPA yesterday proposed new rules designed to cut emissions of soot and smog-causing pollutants by up to 90 percent from heavy-duty commercial trucks and super-large sport utility vehicles. The proposal aims to close a loophole that exempts the largest SUVs, such as the Ford Excursion and Chevy Suburban, from meeting the same emissions requirements as cars and light trucks. The EPA also said it plans to compel the U.S. petroleum industry to produce cleaner diesel fuels. The new requirements, which will be laid out in detail later this year or early next, would kick in beginning in 2007. They would cut exhaust so dramatically that a diesel bus or truck would be as clean as one that runs on natural gas.