Monday, March 28, 2011
Strategic Tractor Operation Can Save Fuel
Diesel fuel is expensive and will be one of your 2011 inputs with the greatest cost increase over 2010. In fact, Kansas State University economist Kevin Dhuyvetter says April prices will be 27% more than April of last year, and May diesel fuel prices will be 34% over last year. You may have already filled your farm tanks but when they are empty the price will undoubtedly be higher. To counteract that higher expense, plan to operate your tractors this spring with the intent to save 10% or more on your fuel consumption.
There is little you can do about fuel prices, other than plug Dhuyvetter’s price forecasts into your budget. However there is something that you can do about the fuel you consume. Iowa State University ag engineer Mark Hanna says drive your tractor as you do your car or pick up on the highway and that is to shift up and throttle back. In other words, move to a higher gear to maintain the speed you need to achieve, but reduce your engine RPM.
Tillage operations, planting, and spraying all require varying amounts of drawbar force, which is dependent on the drag from your equipment and the soil conditions. Depending on what gear you are working in and the engine RPM, you may not be fully loaded, but are burning fuel as if you were fully loaded. Hanna says that is what you want to adjust.
You may have a new tractor that will make the adjustments for you without you even knowing it. Those tractors come with a sophisticated transmission that functions as a continuously variable transmission and electronically selects the gear and throttle setting depending on the load it is pulling. You paid a lot of money for that technology, so make sure it works for you, including greater fuel efficiency. That might be a feature you should seek if upgrading to a newer tractor.
If your tractor is not outfitted with that feature, you will have to take more responsibility for selecting the correct gear and throttle setting. The gear up and throttle back practice has been confirmed as a fuel efficient practice by the Nebraska tractor tests. Those tests are detailed in Hanna’s fact sheet which uses a Case IH Magnum 245 operating in 7th gear with maximum drawbar power as an example. “If the tractor continues to use 7th gear when operating at a reduced load of 75% of maximum available drawbar power fuel consumption is 11.6 gal/hr at 2090 engine RPM. If the same load is pulled in 9th gear but with a throttle setting reduced to 1580 engine RPM (to maintain the same travel speed and drawbar power output) only 10.5 gal/hr is consumed – a 10% fuel savings.” The tests indicate a 20% fuel savings if the load is only 50% of drawbar power, and the transmission is shifted up to 9th gear and engine speed cut to 1620 RPM.
Hanna says if you shift too high and cut your engine speed, a significant increase in black smoke indicates it has been overloaded. The sound of the engine being labored will also be an indicator that you have shifted too high in an effort to save fuel.
He says the practice can be implemented any time that the available tractor drawbar power exceeds the demands of the load. For example, that may be a light tillage operation or the use of a smaller planter. He says it could also be practiced with a pull type sprayer if the sprayer pump is not dependent on the tractor PTO. If a tractor is pulling a baler or mower needing a standard PTO shaft speed, then the shift up and throttle back practice should not be used.
Summary:
With higher costs of diesel fuel, increased fuel efficiency will help reconcile many farm budgets. That reduction in fuel consumption can come by reducing engine speed, but shifting to a higher gear to achieve acreage coverage that is needed. Many times, field operations are conducted at full throttle and a drawbar demand that is less than what is being provided by the tractor. That situation will waste fuel. However working with throttle and gear settings designed to maintain needed speed at a lower engine RPM will allow you to increase your fuel efficiency.
Posted by Stu Ellis on 03/28 at 12:00 AM | Permalink