Have Tractors gotten more or less fuel efficient in the last 10 years? Canada's tractor test lab, The Prairie Ag Machinery Institute, averaged the ratings for the six most common 100-hp tractors sold in Canada in 1975 and 1995. The study showed a 16.5% improvement in tractors between 1975 and 1995, as fuel consumption (at rated rpm) rose from 14.93 to 17.40 hp-hr./gal.

“Some of the first emission-reduction strategies included electronic fuel injection, which, although costly, does lead to better fuel use,” says Roger Hoy, director of the Nebraska Tractor Test Lab, University of Nebraska-Lincoln. “I would speculate that during the 1975 to 1995 period, improvements in fuel economy may well have occurred due to this sort of technology.”

But what about today? For this story, Hoy compared tractors between 100 and 200 hp that were tested in the last 10 years. He found no obvious trend either up or down. Some tractors have significantly improved, due to the change from a two- to a four-valve cylinder head for emissions. Others have gotten worse. Generally, increased emission standards have a slight negative effect on fuel economy. And technologies such as the continuously variable transmission (AGCO) or the infinitely variable transmission (Deere) may provide better fuel economy at the lower horsepower levels than traditional tractor transmissions provide.