In the last 30 years, tracks have become a mainstay at farm shows and new product launches — from tractors and combines built from the ground up for tracks to aftermarket products to convert tire systems to tracks. The advantages are often touted as reduced compaction, especially when working with fine, poorly drained soils, along with better drawbar pull and improved fuel efficiency.

But are these advantages worth the added expense for your specific situation? Research at the University of Nebraska-Lincoln's Nebraska Tractor Test Lab in 2012 suggests both tires and tracks have their advantages, depending on the soil type and climate.

In 2012, NTTL began a study to observe how tires and tracks perform under different field conditions and load scenarios. For this particular study, a Case Steiger 600 and Case Steiger 600 QuadTrac were used.

On concrete, tires outperformed tracks in fuel efficiency. The tire-equipped Steiger 600 had a fuel efficiency of 17.52 hp-hours per gallon, compared to 16.70 hp-hours per gallon on the QuadTrac on similar power and travel speed. "Tires were almost an entire gallon more efficient. The tires weigh less than the track machines in that situation, which is part of it," says Roger Hoy, UNL biological systems engineering professor and NTTL director. "At least on pavement, which is not where tractors really operate most of the time, tires are more efficient."

Real field conditions
How about real field conditions? NTTL also tested the two tractors on dry wheat stubble immediately following harvest, using a lighter drawbar load of about 21,000 pounds. In this scenario, the fuel consumption differences were similar to concrete — about 14.79 hp-hours per gallon with tires and 13.76 on tracks.

After tilling the field and plowing the stubble under, tracks performed slightly better with a similar drawbar load — about 13.3 hp-hours per gallon, compared to 12.71 with tires. That gap continues to close as field conditions get wetter.

However, where tracks really shine, Hoy adds, is on heavier payloads (upward of 29,000 pounds) combined with bare soil conditions. "When we went to a heavier load of about 29,000 pounds in dry wheat stubble, there was a slight performance advantage to tires [about 14.39 hp-hours per gallon compared to 14.09]," Hoy says. "When we went to the tilled field, the tracks started surpassing tires at 29,000 pounds."

At moist field conditions at heavier payloads of about 25,000 pounds and 29,000 pounds, tracks outperformed tires by about 1 hp-hour per gallon. At 29,000 pounds in moist field conditions, tracks outperformed by 14.21 hp-hours per gallon, compared to 13.23. At even more moist conditions at a 25,000 payload, about 13.92 to 12.90.

Dry vs. wet soil
"The general conclusion was the tires seemed to do better in dry soil conditions, but tracks offer fuel economy savings when you're in heavier draft and wetter soil conditions," Hoy says. "There's probably a little higher cost to tracked machines vs. wheeled machines. But in heavier draft loads, especially in wetter conditions, there is a significant fuel savings for tracks."

What does this mean for the farmer? It depends on the size of tractor and the production system. Horsepower-hour per gallon is a function of observed horsepower over observed gallons per hour — a higher number means higher fuel efficiency. This way, tractors can be compared even when actual fuel consumption and power delivered are somewhat variable.

"In a 12-hour day at a heavy payload and with wet field conditions, you might be saving 15 to 20 gallons of fuel by having tracks vs. tires," Hoy says. "I think it's a significant operating cost. That's something I think farmers need to think about when they're purchasing: What's the cost of operation going to be?"