That Bronco, Jimmy or Suburban doesn’t have to obey the same gas conserving rules your car does. Sport utility vehicles and vans are grouped with pickups, classified as “light trucks” and subject to lower fuel-economy standards…and Diane Steed of the “Coalition for Consumer Choice” says that’s the way it should be.Steed says trucks are made to tow things, haul heavy loads, and carry many people, which makes it difficult to redesign ’em to get better gas mileage. The “Coalition for Consumer Choices” gets some of its funding from truck makers, and some from the Farm Bureau Federation. Steed says cars got smaller and lighter to meet the new standards.She says if minivans, SUV’s and light trucks got smaller, they couldn’t be used for farm work carrying cargo, or big families. Passenger cars made today must get at least 27-point-five miles per gallon of gas, but the mileage standard for vehicles classified as trucks is only 20-point-seven M-P-G. Mark Lambert, president of the Iowa Environmental Council, says standards should be tightened for trucks, too. He says they put just as many pollutants into the air. If they got more miles per gallon, it would mean less gas burned and fewer emissions. Lambert says the argument that fuel-efficient vehicles are lightweight and less safe is outdated.Lambert says engineers have figured out ways to make vehicles fuel-efficient and lighter, but still safer. At issue are proposed changes in “CAFE,” federal Corporate Average Fuel Economy standards, which have remained the same for over a decade.