The federal E-P-A has passed new emissions standards for diesel engines that’ll eventually effect every new farm tractor made or sold in Iowa, but not for several years. Bruce Farrar is spokesman for Indiana-based Cummins, which makes diesel engines. Farrar says the new rules are designed to bring cleaner air in places where off-road diesel engines are used — everything from a farm combine to construction road graders. The so-called “tier four” rules take effect based on horsepower band and start with the zero-to-seven horsepower engines in the year 2008. The rules cover all types of off-road equipment, mandating they achieve emission reductions of over 90 percent. Farrar says the new E-P-A rules are designed to make diesel engines burn cleaner and pollute less. He says the regulations establish very low levels of oxides of nitrogen in particulate matter. The way he interprets the rules, Farrar says Iowa farmers will see the new regulations take effect on new equipment they buy but they will -not- have to change existing machinery. In other words, the current vehicles are “grandfathered” in and will not have to be changed. Farrar says there’s been no discussion of retrofitting in the off-road market so tractors and equipment that are operating today can continue to operate just as they have. New vehicles that are purchased, starting in 2008, will have to comply with the new standards.