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Fuel-saving tips for big savings

While diesel fuel cost does not rank “up there“, taking a fuel miser attitude can add up to significant savings.

Direct seeding is just one way to reduce fuel consumption. Photo by Bruce Barker.

Whether a tractor is 20 years old or rolling off the dealership lot for the first time, a number of fuel-saving measures can be implemented to reduce fuel consumption and prolong tractor life. Lawrence Papworth, a project engineer with the AgTech Centre at Lethbridge, Alberta says that tires, ballast and farming systems are the big three when it comes to saving on fuel. He offers tips on reducing fuel consumption.

Where the rubber hits the ground
The transfer of pulling power from the tractor engine through the drawbar to the ground depends on both correct ballast for proper slippage and tires (or tracks) to grip the ground. Tires should be inflated to the lowest pressure allowed by the manufacture for the load the tires are carrying.  

Over-inflated tires will rut soft soils more easily, decrease traction, wear the tread unevenly and strain the tire material itself. Under-inflated tires increase sidewall wear and raise the risk of side buckling and rim slip. With the correct tire pressure, there is a little more tire on the ground and a bit more efficiency in power delivery.

Papworth recommends using radial tires over bias-ply tires. A North Dakota State University study found that properly inflated radials improve fuel efficiency by six percent over bias-ply tires. Similar results were found in an AgTech Centre study.
Shiny, new black tires are actually less fuel efficient than older, broken-in tires. New tires have longer lugs, which are good for mud, but bad for firm soil conditions. Every time a lug bends, the tractor is using energy that does not add to the efficient transfer of power to the soil. 

Other tire factors that influence fuel efficiency include overloading, type of tire and number of tires used. Overloading causes premature tire wear, excessive soil compaction and increased fuel consumption due to the increased rolling resistance.

Dual tires can also decrease a tractor’s fuel efficiency. Duals are worse than singles and triples are worse than duals. While duals increase flotation and may be unnecessary in good traction conditions, on dry, firm soils, more tires means increased rolling resistance. Where more floatation is necessary, larger dual radials are more efficient than smaller ones as triples. “More tires are less efficient, and we’ve seen that wide single tires are five to seven percent more fuel efficient than narrow duals, although many tractors require duals to support the tractor weight,“ explains Papworth. “Some farmers still like triples, because if they damage a tire, it is cheaper to replace a smaller triple tire than a larger dual.“

Burn less with proper ballasting
Ballasting adds weight to the tractor to help reduce tire or track slippage. Too much ballast means the tractor is carrying too much weight, which cuts into fuel efficiency. It can also cause excessive torque to be transmitted to the tires and ground, causing overload, wear and drivetrain failure.

Papworth says that many tractors are ballasted for the worst-case scenario: a tractor operating at maximum power. However, maximum power is usually only reached 15 to 20 percent of the time, so operating with less ballast could improve fuel efficiency. “The key to ballasting is to decide the speed necessary for an operation and the amount of the load. Then set the tractor weight just heavy enough to pull that load at that speed and at an acceptable slip level,“ explains Papworth. The total tractor weight should wind up being two and a half to three times the load being pulled.

An over-ballasted tractor has a sluggish feel, but an under-ballasted tractor wears tire tread at a faster pace because of excessive slip while never delivering full horsepower to the drawbar, so getting ballast correct is important.

Park the tractor
The best way to cut fuel consumption is to keep the tractor in the shed more often. The move to direct seeding and one-pass seeding has drastically cut diesel fuel costs for many farmers on the Prairies. 

Recent refinements in GPS and auto-steer systems are also shaving fuel costs by reducing or eliminating field overlaps.

Auto-steer can produce upwards of five percent in fuel savings, and it also saves on fertilizer and seed inputs. 

Keeping the air filter clean also helps to reduce fuel consumption. In dusty conditions, clean or replace the air filter frequently, as recommended by the manufacturer.

Tire tips – (Courtesy AgTech Centre)

• A properly inflated radial is six to eight percent more efficient than a bias-ply tire. Radial tires need more management than bias-ply tires. Matching inflation pressures to loads is critical to optimizing the performance of radial tires.
• Do not exceed the maximum permissible operating weight/load for the tractor tires. Consult the owner’s manual or tire manufacturer’s guidebook for recommended pressures for given loads.
• Check all tire pressures regularly.
• Use an accurate pressure gauge for measuring low pressures. Being off by 2 psi (14 kPa) will not have a large effect on performance with tires at 30 psi (207 kPa) inflation pressure, but at 10 psi (69 kPa) pressure, a 2 psi (14 kPa) error means a difference of 20 percent.
• Never exceed 35 psi (241kPa) inflation pressure, as severe damage or personal injury can occur should the tire separate from the rim.
• The pressure recommendations molded into the side of tires are maximum pressures for maximum loads. Using these pressures at less than maximum load can adversely affect tire and tractor performance.
• Always inflate and ballast all tires on the same axle to the same level.
• Remember that changing tire size will change travel speed:  a factor to consider when adjusting ballast to match travel speed.