Tier 4 regulations changed the game. “Every manufacturer has increased manufacturing costs,” says Doug Phillips, product manager, Volvo Construction Equipment. To compensate, new technologies are making wheel loaders easier to operate, more productive and more fuel efficient.
Many technologies match power output to demand, which allows more material to be moved per gallon of fuel consumed. “The days of giving machines as much power as possible are over,” states Bill Campbell, senior product application specialist, medium wheel loaders, Caterpillar. The company claims the largest contributors to its fuel efficiency gains include system integration, new Performance Series Buckets, telematics integration and drivetrain technology and integration.
Systems integration balances the power of the engine, drivetrain and implement systems, resulting in quick response, acceleration and power while significantly improving fuel efficiency. And telematics integration provides more information for the owners and operators.
“For example, we can tell if the operator is using the Cat Engine Idle Management System (EIMS) by how much idling fuel consumption is reported through Product Link,” says Campbell. By simply applying the parking brake, EIMS reduces the idle rpm to about 650 rpm. “Since this size wheel loader idles 30% to 50% of the time, this means up to a half gallon or more of fuel savings per hour.”
Several manufacturers, including Caterpillar, Case, Doosan Kawasaki, Komatsu and Volvo, offer power modes that tailor the power curve of the engine to the work being performed.
“If you want the best performance or you are moving the heaviest or most amount of material, put the machine in power mode,” advises Shane Reardon, Doosan. “That gives you the full function and full capability. Granted, fuel efficiency is not going to be the best at that point.” By switching the power modes from standard to economy, the machine can be slightly de-rated. “So if you are moving light material, whether it is mulch or snow, it will still suffice, but fuel efficiency will be better.”
The ability to set transmission shift points is another common option from suppliers such as Caterpillar, Kawasaki, Komatsu and Volvo. The transmission can be shifted at low engine and wheel speeds when working in flat terrain with low rolling resistance, at high engine and wheel speeds in challenging terrain with high rolling resistance or anywhere in between.
Then there are technologies unique to each manufacturer, such as Volvo’s OptiShift. Standard on 5-yd. through 9-yd. machines, it is comprised of two technologies: a lock-up torque converter and Reverse By Braking.
When operators get efficient, especially in short-cycle loading, they like to use the transmission and torque converter to stop and change direction instead of the brakes. This increases wear on the engine and torque converter, and it builds up heat. Reverse By Braking provides a better solution that is seamless to the operator. When the operator shifts from forward to reverse without applying the brakes, the machine goes to neutral, the engine drops to idle and the brakes are applied. The application of the brakes depends on how far down the operator depresses the accelerator pedal.
Reverse By Braking saves on components and improves cycle times. In addition, there is a fuel savings. “We usually see between 10% and 12% fuel savings in short-cycle loading on machines with OptiShift,” says Phillips. “And the transmission fluid is typically 15° cooler.”
The transmission on Volvo loaders also features an Auto Mode for jobsites with multiple operators. “It sets a shifting pattern designed especially for a particular operator,” Phillips explains. “If I get in the machine and operate it differently than you, it sets a shifting pattern for me.”