The introduction of a new series of “Tier 4” diesel engines, so designated as they comply with new EPA pollution standards, has farmers scrabbling to decipher such terms as SCR (selective catalytic reduction), DPF (diesel particulate filter) and DEF (diesel exhaust fluid). AGCO’s John Rogers offers a brief explanation of the engine changes his company is introducing to meet this Tier regulations during the Ag Connect Expo in Atlanta, Georgia.

"Selective catalytic reduction has actually been around since the late 1970s. We started seeing it on the road in Europe in 2006," Rogers says. "The diesel exhaust fluid is a combination of auto-grade urea. Once it hits the exhaust, we spray that diesel exhaust fluid and vaporize the urea. It breaks down into simple nitrogen and water. It doesn't affect performance."

• VIDEO: Agriculture.com's Dave Mowitz talks Tier 4 with AGCO's John Rogers

Engineers have been gearing up to major changes to diesel engine design for over a decade in anticipation of meeting EPA Tier 4 pollution standard which go into affect this month of 120-horsepower and larger power plants in all agricultural equipment in North American.