Study Results Tell How to Cut Tractor Fuel Expenses

AMES, Iowa – Tractor fuel expenses can add up quickly during fall and spring field work. According to a case study conducted at the Iowa State University Armstrong Research and Demonstration Farm near Atlantic, Iowa, fuel savings of 20 percent or more can be achieved by using the "shift up, throttle back" technique.

Using an auxiliary 12-gallon tractor fuel tank, the study measured diesel fuel consumption for different gear and throttle combinations during disking, plowing and planting with a John Deere 7420 tractor.

“Improving tractor fuel efficiency is one of many ways to reduce energy expenses on the farm,” said Mark Hanna, ag engineer with ISU Extension and Outreach. “For example, using the ‘shift up, throttle back’ technique during planting shows a fuel savings of 21 percent when comparing the lower versus higher gear settings.”

The study also examined the effects of tillage depth on fuel consumption during tandem disking.

“As expected, deeper tillage generally requires more fuel,” Hanna said. “In this case, increasing the disking depth from 3 inches to 5 inches increased fuel use by 9 percent.”

A new publication from ISU Extension and Outreach illustrates the results of the tractor fuel case study from southwest Iowa. Tractor Fuel Consumption at Armstrong (PM 3063B) is available to download from the Extension Online Store, The study summarizes tractor fuel measurements for field work including disking, plowing and planting.

“This case study illustrates a key point about on-farm energy management,” Hanna said. “Many opportunities to improve energy efficiency are tied directly to day-to-day activities such as driving a tractor. Reducing tillage depth and remembering the ‘shift up, throttle back’ technique when you’re in the driver’s seat will reduce fuel consumption.”

For more tips on energy efficiency all around the farmstead, visit or follow @ISU_Farm_Energy on Twitter.

The Farm Energy publications are part of a series of farm energy efficiency resources developed by ISU Farm Energy. This outreach effort aims to help farmers and utility providers to improve on-farm energy management and to increase profitability in a rapidly changing energy environment.