It Used to be that the only time a farmer would think about diesel fuel was when it was time to fill the tank. But as diesel fuel prices soar to $4.00/gal., fuel is becoming an input cost well worth managing. According to the USDA's most recent figures, U.S. farm production expenditures totaled $260 billion in 2007, up 9.3% from the revised 2006 total of $238 billion. Fuel, up 14%, was one of the largest percentage contributors to the increase.

Tractor manufacturers report that customers are beginning to factor in fuel as part of the tractor-buying equation. Farmers are adding fuel efficiency to their list of purchasing criteria, along with the mainstay comparisons of comfort, drive, visibility, performance, dealership service and sticker price. What's more, the American Society of Agricultural and Biological Engineers is currently revising the standard for agricultural machinery management data to include fuel consumption equations.

But just how does a customer determine whether a tractor model is good on fuel? Comparing the fuel efficiency of cars is easy; their miles-per-gallon ratings are listed right on the sales sticker. Tractors are more difficult to rate because their performance is based more on pounds pulled than miles traveled.

For answers, we went to the Nebraska Tractor Test Lab, the officially designated tractor testing station for the United States and a component of the Biological Systems Engineering Department at University of Nebraska-Lincoln. The lab tests tractors according to the codes of the Organization for Economic Cooperation and Development to independently verify manufacturer claims and tractor specifications. Engineers record the performance of the tractor at the main power takeoff, the power lift and hydraulic pump, and the drawbar. Included in the drawbar tests and PTO tests are fuel consumption measurements.

The lab has tested hundreds of models dating from 1920 to the present. We focused on tractors tested beginning in 1999 and looked at the two sizes most common on commercial Midwest crop farms: row-crop tractors from 150 to 299 hp; and high-horsepower 4-wd and track models rated 300-plus hp. Then we used the parameters set forth by the lab (see page 30) to rank them. (Not all makes and models have been tested yet at the lab, and so tractors not tested were not included in our rankings.) Fuel-efficiency ratings for this subset of tractors varied anywhere from 14 to 18 hp-hr./gal.

Just how much difference do the numbers make? Lab Director and Professor Roger Hoy says just 1 hp-hr./gal. can mean a $1,300 difference in fuel costs over the course of a year (see “Dollars Saved,” page 25, for calculations). You must determine whether the fuel savings will ultimately justify a trade-in.

On the following pages are the Top 10 most fuel-efficient tractors tested at the lab in the two size categories studied.