Tractor care and management can bring savings to your farm. By using some simple operating strategies, from correct tyre selection and operating pressure, in addition to regular maintenance, you can bring savings of up to 15% to your farming operations.

Tractor engine designers are working to make their engines more efficient.

That result can only be achieved to its optimum if the field settings and the operational skills are used to ensure that power and fuel is not wasted in the field.

These are important messages for cost-conscious farmers, as are the messages of securing and insuring your farm to protect your assets.

While areas of machinery efficiency, security and insurance may not appear to be linked, they are all part of the often almost hidden costs on a modern farm.

Every farm is different but there are some obvious and simple-to-apply similarities.

They allow for efficiencies that can be incorporated into farm management strategies using simple and repeatable techniques that stand the test of time.

This special Focus supplement serves to highlight the opportunities for more effective management of your farming operations to minimise these costs, while at the same time maximising the opportunities to use farm resources for most secure and productive use.

Machinery represents a significant portion of capital costs, second only to land in many farming operations. A well-kept fleet of machinery improves the ability to respond to changing field conditions and other seasonal needs.

Fuel used in farming machinery represents more than a third of the energy consumed in agriculture. Using fuel-saving measures can play a significant part in reducing input costs and improving farm profitability.

Fuel costs represent about 40% of total costs of the tractor input, based on an annual use level of 450 hours per year. While most farmers do their best to work efficiently, there are usually several improvements that can be made to the way the tractor is set-up, driven and maintained, which together can substantially reduce fuel consumption per hectare.

Most tractor owners are aware of the value of routine maintenance schedules and aim to follow them to protect their equipment investment.

Engine maintenance

Efficient combustion of fuel and air inside the tractor’s engine directly affects the availability of engine power and fuel efficiency.

Filters in tractor engines, both primary and secondary, are used to collect small particles and impurities to protect close machine tolerances inside the engine from wear.

To maintain a proper fuel and air mixture in the tractor’s engine cylinders, filters must be replaced on a periodic basis. If not, then restricted fuel flow starts to impact combustion efficiency.

In one US study at the University of Missouri, farmers were invited to bring their tractors to one of six field days at implement dealers. Over a short period, some 99 tractors were tested using a power-take-off (PTO) dynamometer.

Each tractor was first tested to determine maximum horsepower available through the PTO shaft. A subsequent test was conducted after replacing the existing air and fuel filters with new ones.

After the filters were replaced, average tractor power output increased by 3.5%, without any further modifications. Filters were replaced on all tractors tested, regardless of whether the filters were near the end of useful service life or had been recently replaced.

The reported oil change intervals on the farms were logged. Engine oil samples were collected and subsequently tested to confirm that most tractor operators were following recommended periodic maintenance procedures.

Power tests

The tests on the 99 tractors indicate that scrupulously following air and fuel filter maintenance procedures results in a 3.5% power increase.

Manufacturer representatives confirmed that a 3% to 4% power increase was normal and expected during filter replacement. This proved that consistent filter replacement maintains the tractor’s power output.

This is noteworthy since our recent tractor supplement showed that, at current new tractor costs, each 1hp of tractor power costs approximately €720 per horsepower depending on its size and options.

Making an additional 3.5% of power available on a 150hp tractor is equivalent to adding about 5hp more to the tractor, which is worth nearly €3,500 when considering the initial cost of a new replacement tractor.

Alternatively, fuel flow from the throttle could be reduced 3.5% to produce an equal power level after the filters were replaced. Fuel use savings on smaller tractors being used at the time was estimated to be 450 litres (105 gallons) per year. The researchers found that larger tractors would be expected to save proportionately more depending on use.

Combustion efficiency

Combustion power output in the tractor engine is directly related to air pressure available to fill the combustion cylinder.

A vacuum drop of 0.5psi air pressure, across an air filter results in 3.5% less air entering the cylinder, in a non-turbo engine. The relationship in a turbocharged diesel engine is more complex, but results in a similar trend if oxygen is limited for combustion.

Combustion efficiency is significantly affected by maintaining engine operating temperature within a certain range.

In addition, engine wear increases rapidly if lubricating oil breaks down at high temperatures or water condenses at lower temperatures and reacts with sulphur compounds to create corrosion.

Engine operating temperature should be carefully monitored. Thermostats on many engines open around 80°C (180°F).

Cooling system maintenance should include periodic inspection and replacement of coolant. It should also include possible replacement of the engine thermostat if it is defective in maintaining proper engine temperature.

Letting a diesel tractor engine idle for a few minutes following hard work allows circulation of cooling oil. Before idling for eight to 10 minutes, check the operator’s manual. Newer tractors may require three to five minutes of idling or less.

During road transport, it is advised to lower the tractor engine speed before shut off, which may eliminate the need for idling. Ten minutes of excess idling consumes over two litres of fuel or more on a larger tractor used for tillage.

Ballast and tyres

You need sufficient weight to transmit the tractor’s power to the ground when working in a draft application. The level of ballast required depends on the type of implement being used, the extent of the draft force needed, the working forward speed and the tractor horsepower.

Suggested levels are as follows:

Ballast should be removed from the tractor when it is not required, as a heavier tractor requires more energy to move at a given speed.

Further studies have found that tyre pressure matters for fuel consumption. Savings of between 9% and 12% have been identified, with ploughing and cultivating using tyres at 1 bar pressure rather than 1.6 bar.

Work in the field

The way the tractor and implement is operated in the field can have a dramatic effect on fuel consumption and therefore overall efficiency.

It is generally accepted that there can be up to 15% difference in fuel consumption between operators. To achieve the lowest fuel use per hectare, follow these simple rules:

Implements

Implement set-up can also have a dramatic effect on fuel efficiency. German studies have shown that in ploughing, if the plough is not pulling straight then fuel consumption can be 20% higher than if correctly aligned, while if it is also at the wrong angle, then there can be one third more fuel used.

Similar studies have found significant fuel losses if welded parts are used instead of genuine parts.

Other studies have shown blunt knives on disc mowers can increase power requirement by 20%, while 10% losses have been observed on balers with blunt blades. Wrong tyre pressures have been shown to have a 20% loss of tractive power. All these examples underline the importance of implement alignment and maintenance.

Reducing wheel slip

Special effort should be made to minimise wheel slip. For all draft operations a measure of wheel slip will indicate if balance, ballast and tyre pressures are correct.

Wheel slip should be 8% to 12% for wheel tractors, although up to 15% to 20% in very soft or sandy soils is acceptable. Remember, if you can see wheel slip easily, it is probably over 15%.

If it is not in the normal range, recheck the balance, adjust the ballast if necessary and then reset your tyre pressures. Remember this is only done once for each implement, so write your settings down so you can easily set up the tractor next year.

Measuring economy

Measurement of fuel efficiency is made in litres/ha for tillage applications or litres/tonne for haulage applications. The former is done by reading from the performance monitor on the tractor or calculated by dividing litres/hour by hectares/hour.

Fuel supply

Diesel fuel forms waxy, solid crystals at low air temperatures, common during cold weather operation. The temperature at which diesel begins to cloud as solids begin to form depends on the diesel refining process.

There are doubts among farmers and contractors about the quality of green diesel available in farms.

While low sulphur diesel must be used in all mobile farm machines such as tractors, harvesters and farm handlers, we continue to hear reports that it is not as available as the high sulphur product. Diesel quality remains an issue that is largely outside the control of the farmer or contractor, so select your fuel supplier carefully, based on quality as much as on price.

Keep the fuel tank relatively full during cold weather. If air inside the tank is cooled below its saturation point (dew point), vapour condenses into water and may cause potential fuel problems.

To reduce fuel loss due to evaporation in the summer months, use white or aluminium-coloured paint on above-ground fuel storage tanks. Shade or paint that reflects solar radiation helps to reduce fuel evaporation.

Measuring for success

Recording actual fuel usage is the starting point for making savings. The simplest way to measure fuel usage is to begin with a full tank and then refuel at the end of an activity, recording the filled volume.

On-board computers on some of the more modern tractors can show fuel consumption.

Knowing litres used per hectare, tonne or kilometre is generally more useful than litres per hour.

Common misconceptions

You can try, but there are too many variables. It is almost impossible to get two tractors ballasted exactly the same and even more difficult to get two implements set the same. Also, it is only one of the applications the tractor is used for and does not reflect fuel efficiency in other applications.

This is not possible as soil conditions are never the same from one year to the next and power requirement of implements varies dramatically between soil types, condition and moisture content.

Not true. Think of a car – if you drive faster, fuel use increases.