Many factors affect the fuel efficiency of a wheel loader, including poor maintenance, worn ground-engaging tools and operator inexperience. Yet, the largest variables are ones you can typically control.
"The biggest factors in fuel efficiency are properly trained operators and machine maintenance," says Chad Ellis, product and governmental sales manager, Doosan Infracore.
Machine design is another key component. "Both the machine design and operator play important roles in fuel economy," says Jahmy Hindman, product marketing manager for wheel loaders, Deere & Company. "Poorly trained operators will cause even a good machine design to suffer poor fuel economy, and poor machine design will limit the fuel efficiency well-trained operators can attain. Operators who ride the brakes on wheel loaders cause excessive fuel burn and maintenance to the machine, for example."
Nick X. Tullo, articulated haulers and wheel loaders, Volvo Construction Equipment, adds, "The design of the loader is great, but all the design efforts are wasted if the operator does not utilize the features. I feel the operator will play the most important role."
Adjust operating practices
"Regardless of skill, any operator will benefit by a well-designed machine," asserts Tom Grill, senior application specialist for quarry and aggregate, Caterpillar. "A well-trained operator can also save a substantial amount of fuel based on his or her operating efficiency and awareness of work conditions."
In some cases, an operator can adjust his or her operating style to decrease fuel consumption. "For example, when travelling with a wheel loader, use lower engine speed and possibly a higher gear," he advises. "If you are loading a truck in two minutes and you have to wait one minute for the next truck, then you can adjust your operating style and take more time to load. Lowering engine speed during the travel loaded, dump and travel empty cycle will save fuel."
But sometimes this isn't feasible. "If production is limited by the loader's capabilities, a reduction in fuel consumption is not going to happen. In this case, you want to look at how many tons are moved for each gallon of fuel consumed," says Grill.
Plan the traffic pattern and assign machines to the appropriate jobsites. "Layout of the jobsite to maximize production is key, [along with] making sure the machine is properly sized for the job at hand," says Ellis.
Other simple steps you can take to cut fuel cost while maximizing productivity include maintaining proper tire inflation (under-inflated tires increase rolling resistance) and linkage lubrication (dry pin joints increase the hydraulic pressure required to lift the load), as well as proper matching of loader size to the application.
"The single most important factor to reducing fuel costs for wheel loaders is ensuring the right machine is specified for the application," Hindman states. "This includes factoring in the size of the machine required and equipping the machine properly. For example, for a stockpiling and transport operation, a machine equipped with a lock-up torque converter should be specified to improve fuel economy."
Influence of machine design
There are several different ways machine design can influence fuel consumption.
"Features of a wheel loader that can give the best potential savings in terms of fuel economy include any type of fuel management system or positive flow control/load-sensing hydraulics," says Grill. "In load and carry applications, the lock-up torque converter is a feature that can assist in potential fuel savings."
Some companies offer different working modes. For instance, Doosan has two working modes: power and economy. "Economy mode will save fuel on less demanding jobs," says Ellis.
Deere & Company believes fuel economy begins with the engine design. "Additional design features - like lock-up torque converter transmissions, auto-idle and auto-shutdown, load-sensing hydraulics and variable-speed cooling fans - enhance machine fuel economy regardless of operator capability," says Hindman.