Farm Industry News asked Nebraska Tractor Test Lab Director Roger Hoy and Assistant Director Dave Morgan what factors to use to compare the fuel efficiency of different tractors. You can use these parameters to determine how your models rank.

1. Go to http://tractortestlab.unl.edu. Click on “Test Reports.” The Web site shows all makes and models tested at the lab since 1999. (Hard-copy reports for tractors tested before 1999 are available for purchase. Contact Nebraska Tractor Test Laboratory, Box 830832, University of Nebraska-Lincoln, Lincoln, NE 68583-0832, 402/472-2442, tractortestlab@unl.edu.)

2. Click on make and model of tractor. This will bring up the corresponding test report.

3. Check “Chassis: Type” to determine tractor category (2-wd, front wheel assist, 4-wd, or track). This information is included in the narrative text next to the charts on the site. We ranked tractors in two categories: row-crop tractors (2-wd/front wheel assist) and high-horsepower 4-wd/track tractors.

4. Check horsepower to determine size category. We used PTO horsepower (at rated engine speed) to determine if the tractor belonged to the category of row crop (150 to 200 hp) or high-horsepower 4-wd/track (300+ hp). (See lab chart called “Power Takeoff Performance.”) This is the number used by all manufacturers to verify a claim.

5. Find the rating of horsepower-hours per gallon. The fuel consumption measurement, horsepower-hours per gallon (hp-hr./gal.), has become the standard used for comparing the efficiency of all agricultural tractor models. Measured directly, it means that burning one gallon of fuel in the tractor at full load and at rated engine speed produces a certain amount of horsepower for an hour. The higher the number, the greater the fuel efficiency; that is, more work is being done with a given amount of fuel.

We looked at that rating in two performance tests: power takeoff and drawbar performance. We used results from the “PTO Performance Chart” to establish the fuel-efficiency rankings. The lab says the PTO rating is a good indicator because it is one that is calculated for all tractors and it is always run at the maximum level. However, results from the drawbar performance test are also included, and depending on how you plan to use the tractor, it may be a better indicator of fuel efficiency for some tractors — for example, the very-high-horsepower tractors used primarily for their brute pulling power of, say, deep tillage implements. On the other hand, if the tractor is used primarily for PTO work, then the PTO rating will be your best indicator because it will not be likely to change or won't be as much affected by the size or weight of the implement the tractor is pulling. If you use the tractor for both PTO and tillage work, then consider both ratings in your decision.

PTO performance is measured at several different power levels and speeds, but for comparison purposes, the factor most farmers are interested in is maximum power at rated engine speed. This is the highest power level that the tractor can sustain over a long term and is measured in horsepower. Newer tractors usually have an operating range that includes maximum power at a speed lower than rated. Also, with modern high torque/constant power engines, the power at rated PTO speed is usually similar to the power at the rated engine speed.

Like PTO performance, drawbar performance is measured at different rates of pull and in different gears. Power measured at 75% of pull at maximum power is a reasonable reflection of performance during typical heavy fieldwork. At 75% of pull at maximum power, you will still have some reserve for heavy spots in the field. We list the horsepower-hours per gallon in “third gear” (to show maximum drawbar pull) and “eighth gear” (to show maximum power).

Drawbar tests are conducted on concrete or asphalt test tracks, which allow for consistency in comparison. As a result, the numbers in the test reports are not exactly the numbers you might get in field conditions.
The drawbar ratings listed are for “ballasted” runs. If a ballasted test was not run, then results from the unballasted test (at 1,800 rpm or the lowest engine speed) were used.

In cases where ratings are identical (for example, Case IH and New Holland 4-wd tractors), only one of the tractors was tested and the results serve for both because there was no performance difference between the two.

You can dodge most major machinery breakdowns by regularly inspecting, cleaning and replacing essential components, says Dean Potter, a mechanic at Haug Implement, Litchfield, MN.
"About 80% of the equipment failures I see are due to lack of maintenance or lack of thorough inspection and could have been prevented," he says. "On combines, bearings are the most common things that cause problems."
In addition to checking bearings, Potter recommends inspecting chains and belts on a daily basis. "Look at chains and belts and give them regular adjustments," he says. "Greasing and changing oil are also important. Some farmers are meticulous about that and others aren't."

Those farmers who tend to be the most meticulous about machinery maintenance know that they have a lot to lose if a breakdown occurs, says Potter.

"Smaller, part-time farmers sometimes feel like they can afford to gamble more (on maintenance)," he adds, "because they have less invested in the field."

However, even farmers who operate small acreages should think twice before skimping on maintenance, Potter advises. "The cost of the downtime is typically much higher than the cost of the repair," he says. "There is a cost to maintenance, but generally it comes down to pay me now or pay me later."

Operating conditions, particularly muddy or rocky conditions, can also make a big difference on how often maintenance is needed, says Potter.

"Picking rocks in soybeans can be an important thing to do in some fields," he adds. "Rocks aren't good on combines."
Because combines rely on multiple moving parts, which wear with use, inspections and adjustments are important both prior to and during field operations, says Potter. "Some operators are very much in tune to their machine and to what it can or cannot do," he says. "It helps to take the time to adjust the combine (for different conditions)."
Here are 10 common-sense steps that most farmers can take to avoid combine breakdowns, according to Potter and two agricultural Extension machinery specialists:

1. Start with a preseason inspection. "To avoid breakdowns, farmers need to give their combines a rigorous preseason inspection," says Dan Ess, Purdue University Extension ag engineer. "That's number one. The obvious places to check are chains, belts and bearings."

2. Review your operator's manual. "Check your manual for the appropriate settings for rotor or cylinder speed, concave clearance and fan speed," advises Mark Hanna, Iowa State University Extension ag engineer. "Also check settings for screens in the cleaning shoe."

3. Inspect and clean daily. "Keep bearing surfaces clean of dust and crop residue," says Hanna. "Check for leaks of pressurized oil lines such as those to the turbo charger."

4. Use air, not water. High-pressure air is the preferred cleaning tool for most combine components. "Be careful if using high pressure water to clean the combine, even on the outside of the machine," warns Hanna. "Water forced into interior surfaces can cause rust."

5. Pre-scout fields. Farmers should pre-scout fields for crop size, ear size and weed patches, and be ready to make adjustments as needed, says Hanna. For example, the stripper bar settings on the corn head should have about a 1¼-in. gap for normal settings. For smaller-sized ears, he says that gap should be narrowed.

6. Adjust to field conditions. "As the crop dries down in the heat of the day, fine-tuning can help," says Potter. "Each time you change to a different corn or soybean variety, check to see if you need to make some adjustments."

7. Check grain quality. "If the combine isn't giving you good quality grain, you might have a worn grain elevator chain," says Potter. "If the elevator chain is damaging grain, it could lead to other breakdowns." Feeder house adjustments might also be needed, he adds, if grain quality is deteriorating.

8. Be prepared. Keep a cell phone with you or have some other way to quickly call for help if you need it, recommends Hanna. He also advises having two ABC-type fire extinguishers available on the combine. A 5-lb. model should be in the cab and a 15- to 20-lb. model should be mounted at ground level. Having a small shovel on board the combine can also come in handy to quickly throw dirt on flames.

9. Don't delay repairs. "If you know some things aren't working right, get them worked on right away before you forget," advises Potter. "Proper maintenance starts right at the end of the season before you put the machine away."

10. Clean before storing. Prior to placing a combine in storage for the winter, farmers should clean and remove the battery and place it in a heated storage area where it won't freeze, says Hanna. He also advises giving the combine a good, overall cleaning.

"Also before harvest, make sure the skid plates under the grain platform are clean, and check that they give you a full range of movement," says Hanna. "Clean under the corn snouts on the corn head and check and clean the gathering chains. Also clean any accumulated debris on the cooling fins on the radiator, the hydraulic oil cooler and the air conditioner condenser."
Inspect Combine Components Before Harvest

To help in efforts to clean and adjust your combine prior to harvest, Mark Hanna, Iowa State University Extension ag engineer, has developed a preseason combine component checklist.
You may also want to keep and expand on the following checklist as you review your operator's manual prior to harvest:
• Air conditioner (clean cooling fins, check the drain tube for plugs)
• Auger spirals (look for worn or bent flighting on cross augers and unloading augers)
• Battery (check, clean)
• Bearings (check wear, condition)
• Cleaning shoe (clean, adjust, lubricate as needed)
• Corn head (check condition of ear savers)
• Cutter bar (check flexibility and movement)
• Cylinder or rotor rasp bars (check manual for allowable wear)
• Drive belts (check for tension, look for excessive wear and cracks)
• Feeder house (adjust setting of lower drum, inspect sheet metal on underside for holes, cracks or worn or thin material, and replace if needed)
• Filters (replace)
• Fluid levels for engine oil, coolant, hydraulic fluid and gear case oil (check both condition and amount)
• Gathering chains (clean, check tension and condition)
• Grain bins (clean with a shop vacuum)
• Grain platform (check knife sharpness and wear, examine for full back-and-forth cut)
• Lights (clean, replace bulbs)
• Reflector tape (clean and/or replace)
• Rubber paddles on grain elevator (check for wear /condition)
• Skid plates under grain platform (check for full range of movement)
• Stripper bar (check settings)
• Slip clutch (check operation and bolt condition — look for broken or sheared bolts)
• Tires (check air pressure, tread wear and condition).

"Honestly, the biggest things that I see when it comes to increasing a tractor's life expectancy are the routine maintenance issues," says Mark Hanna, Extension agricultural engineer at Iowa State University. "Things like fluid and filter changes may not be a glamorous job, but they are the most critical aspect of getting the most out of your equipment."

And Hanna says it's not just the engine that producers should pay attention to. "The engine, power transmission and drivetrain are all working together, and they all need regular maintenance and inspection to ensure they are working efficiently."
And letting an oil change or air filter cleaning linger longer could also be costing in reduced hp.

"Recently, we were developing a tractor maintenance bulletin and we looked back at a study done a number of years ago where tractors were tested for power efficiency before and after filter and fluid changes," Hanna says. "Producers brought a tractor in, and it was hooked up to a dynamometer before service and after service. That study showed that, on average, producers had a 3 1/2 percent power increase after routine maintenance."

So for a 200 hp tractor, a 3 1/2 percent power increase means 7 hp. And given that, on average, producers are spending $650 to $700 per hp on new tractors, producers who don't regularly service filters and fluids could be costing themselves as much as $4,900 by not sticking to a regular maintenance schedule.

"That's a significant number," Hanna says. "And that goes beyond the additional wear and tear that we can see with tractors that aren't properly maintained."

Stretching oil change intervals can have varying degrees of impact, depending on how the tractor is being used and how long the time between oil changes. "Various additives are in the oil to mitigate contaminants and the oil can handle it for a certain amount of time," Hanna says. "But as additives are consumed, there will be increased wear and tear on the tractor. You might be able to get by for a time, but it will have an impact on tractor life."

Routine maintenance can also come up during the most critical production times — planting and harvest, when producers are expecting the most out of their equipment and usage is highest. That's when keeping track of service and maintenance intervals can sometimes creep down on the to-do list.

"That's when a good team relationship with the producer and dealer comes into play," Hanna says. "Working together, they can develop a service plan that ensures schedules are met."
For more information on tractor maintenance at Iowa State, visit: www.extension.iastate.edu/Publications/PM2089L.pdf

1. Go to http://tractortestlab.unl.edu. Click on "Test Reports." The Web site shows all makes and models tested at the lab since 1999. (Hard-copy reports for tractors tested before 1999 are available for purchase. Contact Nebraska Tractor Test Laboratory, Box 830832, University of Nebraska-Lincoln, Lincoln, NE 68583-0832, 402/472-2442, tractortestlab@unl.edu.)

2. Click on make and model of tractor. This will bring up the corresponding test report.

3. Check "Chassis: Type" to determine tractor category (2-wd, front wheel assist, 4-wd, or track). This information is included in the narrative text next to the charts on the site. We ranked tractors in two categories: row-crop tractors (2-wd/front wheel assist) and high-horsepower 4-wd/track tractors.

4. Check horsepower to determine size category. We used PTO horsepower (at rated engine speed) to determine if the tractor belonged to the category of row crop (150 to 200 hp) or high-horsepower 4-wd/track (300+ hp). (See lab chart called "Power Takeoff Performance.") This is the number used by all manufacturers to verify a claim.

5. Find the rating of horsepower-hours per gallon. The fuel consumption measurement, horsepower-hours per gallon (hp-hr./gal.), has become the standard used for comparing the efficiency of all agricultural tractor models. Measured directly, it means that burning one gallon of fuel in the tractor at full load and at rated engine speed produces a certain amount of horsepower for an hour.

The higher the number, the greater the fuel efficiency; that is, more work is being done with a given amount of fuel.
We looked at that rating in two performance tests: power takeoff and drawbar performance. We used results from the "PTO Performance Chart" to establish the fuel-efficiency rankings. The lab says the PTO rating is a good indicator because it is one that is calculated for all tractors and it is always run at the maximum level. However, results from the drawbar performance test are also included, and depending on how you plan to use the tractor, it may be a better indicator of fuel efficiency for some tractors — for example, the very-high-horsepower tractors used primarily for their brute pulling power of, say, deep tillage implements. On the other hand, if the tractor is used primarily for PTO work, then the PTO rating will be your best indicator because it will not be likely to change or won't be as much affected by the size or weight of the implement the tractor is pulling. If you use the tractor for both PTO and tillage work, then consider both ratings in your decision.

PTO performance is measured at several different power levels and speeds, but for comparison purposes, the factor most farmers are interested in is maximum power at rated engine speed. This is the highest power level that the tractor can sustain over a long term and is measured in horsepower. Newer tractors usually have an operating range that includes maximum power at a speed lower than rated. Also, with modern high torque/constant power engines, the power at rated PTO speed is usually similar to the power at the rated engine speed.

Like PTO performance, drawbar performance is measured at different rates of pull and in different gears. Power measured at 75% of pull at maximum power is a reasonable reflection of performance during typical heavy fieldwork. At 75% of pull at maximum power, you will still have some reserve for heavy spots in the field. We list the horsepower-hours per gallon in "third gear" (to show maximum drawbar pull) and "eighth gear" (to show maximum power).

Drawbar tests are conducted on concrete or asphalt test tracks, which allow for consistency in comparison. As a result, the numbers in the test reports are not exactly the numbers you might get in field conditions.
The drawbar ratings listed are for "ballasted" runs. If a ballasted test was not run, then results from the unballasted test (at 1,800 rpm or the lowest engine speed) were used.

In cases where ratings are identical (for example, Case IH and New Holland 4-wd tractors), only one of the tractors was tested and the results serve for both because there was no performance difference between the two.

It's going to cost you more to grow your corn and soybean crops this year, but with the general trend in the grain markets lately, that added expense should be worth it, according to new crop margin data from Purdue University.

Two Purdue economists find rising input costs -- namely fertilizer and fuel -- have the average per-bushel production cost for corn around $4.19 per bushel. That's up 30 cents from a year ago. The jump in soybean production costs is around 33 cents per bushel at $9.73. The numbers, say Purdue ag economists Craig Dobbins and Bruce Erickson are based on "average-quality land" that's capable of raising 161-bushel corn and 49-bushel soybeans.

Last October, Purdue specialists estimated corn fertilizer costs to be around $134 per acre. That's up to $151 per acre in the most recent figures. Soybean fertilizer costs are seen up $7 to $69 per acre in that same timeframe.

"Fertilizer prices seem to be one of those areas where the cost increases are most noticeable," Erickson says in a Purdue report. "Even though fertilizer prices are up compared to last summer, if you look at them relative to grain prices they're not terribly out of line."

Though crop insurance premiums won't be set until early next month, Dobbins also expects them to move higher. But, 2011 is not a good year to trim your insurance investment, he advises. Why? Since October, per-bushel prices are up 74 cents for corn, $1.52 for soybeans and $1.21 for wheat. That kind of upward movement in prices indicates farmers shouldn't sell crop insurance short, Dobbins says in a university report.

"We're in an environment where that's not a place to think about saving costs this year," he says. "It's an issue of finding the policy that you think will work best for you and pay the premium."

One bright spot on the cost side is grain drying costs. Propane prices have slipped since last fall -- Erickson and Dobbins expect corn drying costs to be closer to $26 per acre versus last fall's estimate of $33 per acre.

So, taking these cost variables into account, the Purdue economists say profit margins are still "quite large." That means the time between now and planting is a good time to make sure those margins stay intact.

"At this point in time, contribution margins -- the difference between gross revenue and production costs -- are really quite large," Dobbins says. "If one is looking for a place to expend energy from now until you can get out into the field and plant, I think one ought to focus that energy on protecting the margin that you've got in crop production today."

If your combine's leaving corn on the ground in your fields this fall, you're doing more than just losing yield. You may be creating ideal conditions for a disease that's run rampant through fields around the Midwest this year.

In this year's corn fields that will become next year's soybean fields, corn kernels left on the ground this year could help sudden death syndrome (SDS) get a head-start next year, says one ag engineer.

"Leaving corn in the field during harvest always results in a yield penalty. A recent soybean SDS article shows data that suggest corn kernels may be one of the most likely sites for survival of SDS pathogens with potential to harm subsequent soybean crop," says Iowa State University (ISU) ag engineer Mark Hanna.

Minimize that possibility by keeping your corn head calibrated for the field conditions you're encountering, Hanna says. That means in-field checks for both ears and kernels.

"Be particularly aware of dropped ears as hundreds of kernels are lost in a single ear drop. Finding just one ear by kicking through residue in a 20 x 22 foot area behind an 8-row cornhead equals one bushel per acre loss," Hanna says. "Ear-saver tabs or shields commonly found at the lower end of stalk rolls should be maintained and excessive harvest speeds avoided to keep ear losses down."
Check the deck or snapping plates that shield the stalk rolls and adjust them according to the ear size in the field you're running, Hanna adds. Kernels can typically be left in the field when you're shelling corn "when the butt end of the ear is allowed to contact stalk roll.

"A good starting point for today's corn hybrids is about 1 1/4-inch gap between plates to allow stalks to move through between deck plates, but ears to be snapped before contacting stalk rolls," he says. "It may be advantageous to allow a slightly wider gap at the top/rear of plates so that stalks don't wedge."

On newer machines, that gap between deck plates can be hydraulically adjusted from the cab, eliminating the need to manually adjust between fields. That being the case, Hanna says the best way to check is by stepping into the field every now and then.

"Take a few minutes periodically to check and measure losses on the ground. Perhaps disease pathogen survival offers another reason to limit corn loss in the field this fall," he says.

Last February, Caterpillar president Stu Levenick put impending EPA Tier 4 pollution restrictions in perspective. He said they’d caused his company to take on “the most aggressive and expensive product development initiative in Caterpillar history.”
This comes from the firm that innovated the crawler tractor.

Modifications made to diesels since emissions restrictions took hold in 1996 rival any advance made to machinery since Rudolph Diesel’s introduction of a compression-ignition engine in 1892. “Deere & Company spends about $2.5 million a day on research and development,” says Steve Meinzen of that firm. “In recent years, a significant share of that enormous investment has gone to developing Tier 4 interim engines.”

The environmental payoff is stunning. By EPA estimates, modifications made to diesel to date have cut nitrous oxide (NOx) smog by 1 million tons per year. That is the equivalent of taking 35 million cars off the road.

This is just the beginning. Come January 2011, diesels 175 hp. and larger must meet new Tier 4 interim standards. When the Tier 4 final level is completed in 2015, all diesels, regardless of horsepower, must eject 90% less NOx and 90% less particulate matter (PM). This challenges engineers as never before. In their tightrope walk between the Tier 3 and Tier 4 platforms, designers have a delicate balancing act between NOx and PM. That is where the latest postcombustion treatments now installed on diesels come into play.

One path used to meet Tier 4 interim standards employs exhaust gas recirculation (EGR) to control NOx. This approach still turns out unacceptable levels (by Tier 4 interim levels) of PM. But that soot (unburned fuel) is captured and burned off in a catalytic filter that is part of the engine’s exhaust system.

An alternative technology meeting Tier 4 final rules is selective catalytic reduction (SCR). This approach injects diesel exhaust fluid (DEF) into the engine’s exhaust stream to neutralize excessive NOx. PM output is slashed by tuning the engine to thoroughly combust fuel.

Farmers will literally be able to breathe easier thanks to these advances – but at a cost. Only Caterpillar has estimated its price tag to meet Tier 4, calculating it will add 12% to engine costs over the next three years. Other manufacturers hint at price hikes for whole machines in the 3% to 5% range.

Yet there is a payoff for this extra cost. Cleaner burning engines are more efficient; they drink 15% to 20% less fuel than pre-Tier power plants built 12 years ago. New efficiency records are set at the Nebraska Tractor Test every year. The latest mark breached is 20 hp. hours per gallon. A Massey Ferguson 8680 exceeded that output last year. Indeed, today’s diesels churn out torque levels not possible a decade ago and leap to grow more power in a split second.

The Brain Box
There isn’t a function on today’s diesels that isn’t regulated by the electronic control unit (ECU). Also called the electronic engine control (EEC) or electronic control module (ECM), these brain boxes constantly regulate all aspects of engine performance like injection pressures and timing, turbocharger operation, combustion chamber temperature, levels of nitrous oxide (NOx) or particulate matter (PM), and even engine timing. This breakthrough has made it possible for engines to burn less fuel and eject fewer pollutants while spurring them on to generate surprisingly tall and long torque curves.

General relationships capable of predicting tractor diesel fuel consumption are very useful for budget and management purposes but may not have the ability to compare fuel consumption for several potential engine configurations, such as turbocharging and air densification components. The objective of this factsheet is to examine several methods that use field measurements and Nebraska Tractor Test Laboratory results to estimate fuel consumption. Using these equations, farmers can estimate and compare the fuel savings for different operating and loading conditions.

Introduction
According to Siemens and Bowers (1999), “Depending on the type of fuel and the amount of time a tractor or machine is used, fuel and lubricant costs will usually represent at least 16 percent to over 45 percent of the total machine costs. …” Thus, fuel consumption plays a significant role in the selection and management of tractors and equipment. Currently, most budget models use a simplified method for estimating diesel fuel consumption. Better estimates representing actual field operations are needed to compare machinery management strategies.

The worth of a tractor is measured by the amount of work that can be accomplished and the cost associated with completing the task. Drawbar power is defined by pull (or draft) and travel speed. An ideal tractor would convert all fuel energy into useful work at the drawbar. However, due to power losses, not all fuel energy is converted into useful work.

Efficient operation of farm tractors includes (1) maximizing the fuel efficiency of the engine and the mechanical efficiency of the drivetrain, (2) maximizing tractive advantage of the traction devices, and (3) selecting an optimum travel speed for a given tractor-implement system. This factsheet focuses on methods to estimate and improve fuel efficiency of a diesel power unit.

The Nebraska Tractor Test Laboratory (NTTL) has a long history of testing tractors and disseminating power and fuel consumption data. The NTTL is the official testing station for agricultural tractors in the United States. Tractors manufactured in the United States and other countries are tested, and NTTL publishes the test results. During standardized tests, the power is calculated and the corresponding fuel consumption is measured. The power at the power takeoff (PTO) is calculated from the torque and speed at the PTO. Drawbar power is calculated from the drawbar pull and the forward speed of the tractor. For more details and for a sample test report, see Using Tractor Test Data for Selecting Farm Tractors, Virginia Cooperative Extension publication 442-072.

Terminology
Tractor manufacturers specify power output at several tractor locations, such as power takeoff, drawbar, hydraulic outlets, and electrical outlets. For each tractor model, the rated power output is measured at the rated engine speed. Typically, this power is measured at the PTO, and in this factsheet, it is referred to as “rated PTO power.” For most modern tractors, the rated power will not be the maximum available power. Most modern engines often produce more power because they can be operated at speeds other than rated speeds.

Fuel consumption is measured by the amount of fuel used during a specific time period. The most common measure of the energy efficiency of a tractor is referred to here as “specific volumetric fuel consumption” (SVFC), which is given in units of gallons per horsepower-hour (gal/hp-h). Specific volumetric fuel consumption is generally not affected by engine size, and it is used to compare the energy efficiencies of tractors with different size engines and under different operating conditions. SVFC for diesel engines typically ranges from 0.0476 to 0.1110 gal/hp-h.

For ease of computation, the reciprocal of SVFC is often used and is referred to here as “specific volumetric fuel efficiency” (SVFE) with units of horsepower-hours per gallon (hp-h/gal), with corresponding ranges from 12 to 21 hp-h/gal.
The NTTL reports the SVFE for several drawbar load tests, rated PTO speed, and varying PTO power tests. Figure 1 shows sample data from an NTTL report. The SVFE for this test is shown under the columns labeled with units of hp-h/gal (kW-h/L). For example, at rated engine speed, the tractor shown in figure 1 developed 115.96 PTO horsepower with an SVFE of 17 hp-h/gal.

The data measured in NTTL Report 1725 (shown in figure 1) is used to demonstrate the computation for equation (4). For the drawbar performance at “75% of Pull at Maximum Power,” the engine speed was 2,190 rpm, and the SVFE was 12.80 hp-h/gal. The corresponding test with a reduced throttle setting had an engine speed of 1,665 rpm and an SVFE of 14.63 hp-h/gal. The SVFC was calculated as 0.0781 gal/hp-h for full throttle and 0.0684 gal/hp-h for the reduced throttle test. The decrease in SVFC was 12.4 percent, while the engine speed was reduced by 24 percent. Similarly, the “50% of Pull at Maximum Power” tests resulted in a 24 percent reduction in engine speed and a 15.8 percent decrease in SVFC.

Tractor Fuel Efficiency Improvements
Newer tractors are generally more efficient than models produced 20 years ago. Improvements in fuel efficiency during the last 20 years prove this point. Figure 2 shows the average and maximum specific fuel consumption of tractors tested from 1980 to 2000. Models tested in 2000 averaged 16.5 hp-h/gal, compared to an average of 14.5 hp-h/gal for models tested in 1980. The fuel savings of 10 to 15 percent became possible because of improved engine/transmission design and improved ability to match tractors and implements for given field conditions. Today’s tractors have more electronic controls for more efficient delivery of power to the PTO, drawbar (for pulling), and hydraulic lifts and controls.

The reduction in fuel efficiency seen during years 1991, 1998, and 2004 (figure 2) is attributed to the new emission requirements that went into effect for off-road vehicles. Even though Environmental Protection Agency (EPA) regulations initially challenged engine designers, fuel efficiency has improved significantly since then. All tractors are not equal in fuel consumption. The maximum value line in figure 2 represents the fuel efficiency for the most fuel-efficient tractor for that year. The fuel consumption data is an important consideration during the selection and purchase of a tractor.

Fuel Consumption Estimates
ASABE Standards (2006, 2009) are widely used for estimating fuel consumption for budget preparations. The most widely used relationship for estimating fuel consumption in gallons per hour (gal/h) is
QAVG = a? • PPTO (1)
where
QAVG = average diesel consumption (gal/h),
PPTO = rated PTO power (hp),
a? = 0.044 gal/hp-h.
Bowers (2001, e-mail correspondence) stated that equation (1) was developed based on PTO power test results from the Nebraska Tractor Test reports during the mid-1970s. The fuel consumption (gal/h) over the varying PTO power tests (approximately 100 percent, 85 percent, 65 percent, 45 percent, 20 percent, and 0 percent of rated PTO power) were averaged, then the average was divided by the rated PTO power. For this reason, the annual fuel consumption estimates using this method give fuel consumption based on the assumption that the tractor is operated under the same load pattern for equal time. Due to this assumption, this method underestimates fuel consumption.
For the complete article click here

Source: AGCO News Release

DULUTH, Ga. (August 5, 2010) — AGCO has introduced a variety of new products for tech-savvy professional producers and agricultural retailers.

The new products offer innovative features created through AGCO’s customer-driven research and development efforts. Each piece of equipment is proof of AGCO’s commitment to bringing agriculture customers advanced technology and innovative products that will help each of them be efficient, productive and profitable.

These new products will be on display at industry events and farm shows this fall.

AGCO Introduces Sunflower 1550 Series Five Section Disc Harrows

The all-new Sunflower 1550 Series five section disc harrows are built with ground-breaking technology not found on any other piece of tillage equipment. The patent-pending duplex wing hinges and walking triple tandems are two of the innovative features on the Sunflower 1550 Series that help growers cover more acres and break through the toughest soil environments in the corn and wheat belts. News Release

AGCO Application Equipment Unveils New TerraGator 6303 and 8303 Models
The new TerraGator models 6303 and 8303 from AGCO Application Equipment have been designed to make the industry’s hardest-working flotation applicator even more productive with key features such as the innovative AGCO Continuously Variable Transmission (CVT), AGCO SISU POWER™ 8.4 liter diesel engine, and cab improvements. News Release

New Drive System Strengthens Industry-Leading RoGator Lineup
The experts at AGCO Application Equipment are rolling out five new RoGator high-clearance applicators for 2011. The critical new feature is a proven drive system that AGCO has engineered to deliver even higher levels of performance and reliability in the field.

Rising Diesel Fuel Costs, Tougher EPA Regulations Create Challenges for Farmers
With the Environmental Protection Agency’s (EPA) Tier IV interim (Tier IVi) emissions standards for off-road vehicles rapidly approaching, many farmers are concerned about environmental compliance. At the same time, they’re keeping a watchful eye on rising diesel fuel prices and wondering how the engines of these new “environmentally friendly” row-crop tractors will fare in terms of performance and fuel efficiency.

An increasing number of growers have found that new engine technologies can keep emissions in check while also delivering outstanding performance and fuel efficiency. A perfect example is the AGCO SISU POWER 8.4 L engine with e3™ selective catalytic reduction (SCR) clean-air technology that is found in Challenger® and Massey Ferguson® high-horsepower row crop tractors.

The company says it plans to begin shipping the new units to its dealers in March for all three of its brands of high-horsepower tractors - AGCO, Challenger and Massey Ferguson - in the 270-350 horsepower range.

The company is branding the new off-road diesel engine technology as e3, which stands for energy, economy and ecology. The new diesels utilize SCR (selective catalytic reduction) technology that the company describes as "a simple, robust and proven method for treating diesel exhaust emissions to achieve EPA emissions standards."

Selective Catalytic Reduction (SCR)
SCR is a proven emission-control system designed to lower emissions of nitrogen oxide (NOx) and particulate matter (PM) from the exhaust gases of diesel engines.
e3 is a post-combustion, after-treatment process that takes place within the exhaust system itself. With the e3 system a NOx reducing agent, or Diesel Exhaust Fluid (DEF), is injected into the exhaust gas upstream of the e3 catalyst chamber.
When heated, a liquid urea solution, the active ingredient in DEF, turns to ammonia and reacts with NOx from the exhaust to convert the pollutants into nitrogen, water vapor and tiny amounts of carbon dioxide (CO2). The company reports that e3 technology alone can achieve NOx reductions in excess of 90%.

The key to the success of e3 is the fact that it's a post-combustion process. It stays out of the way of what the engine is built to do - provide power. After the exhaust leaves the engine, all that remains is to reduce the nitrogen oxides (NOx). Because only the exhaust gases are treated, e3 SCR technology allows engineers to use the most efficient engine settings for optimum power and fuel economy.

A Proven Technology
AGCO SISU POWER and AGCO engineers selected SCR technology because, the company says, it is widely acknowledged as the most effective and fuel-efficient method of meeting present and future EPA emissions requirements. SCR exhaust gas after-treatment was originally used to reduce NOx emissions from coal-fired power plants and has been widely used in the trucking industry.

In North America, several truck manufacturers have selected SCR, including Mack, Volvo, Cummins, PACCAR and Detroit Diesel, to meet the 2010 emission control standard for on-road diesel engines.

AGCO reports that it is currently used on more than 500,000 diesel-powered vehicles in Europe. It is also the system preferred by leading on-highway vehicle manufacturers including the market leader – Mercedes-Benz as well as BMW, Audi, Volkswagen, Mini, Hyundai, Kia, and Jeep.

Diesel Exhaust Fluid (DEF)?
Diesel Exhaust Fluid (DEF) is a solution of purified water and 32.5% automotive-grade urea. DEF works with the heat of the exhaust in the catalytic chamber and converts nitrogen oxide (NOx) from diesel exhaust into nitrogen and water.
DEF is metered in precise quantities and then injected, via a Bosch control system, into the exhaust system that includes a catalytic chamber. The DEF is carried in a separate tank on board the tractor and is consumed at a rate of about 3% DEF/gallon of diesel fuel.

It is the equivalent to 3% of the fuel used. Therefore, for every 100 gallons of fuel used, 3 gallons of DEF will be consumed. Typically a farmer will fill his DEF tank every second fuel fill up.
In Europe, DEF is marketed as AdBlue.

According to AGCO, thousands of supply locations are springing up across North America. Since the trucking industry has already adopted SCR technology to meet the EPA Tier IV emissions requirements, availability at truck stop chains is spreading nationwide. DEF will also be available through AGCO, Massey Ferguson and Challenger dealerships.