With fuel costs continuing to take a big bite out of construction companies’ profitability, manufacturers are responding with enhancements designed to increase fuel efficiency with the additional benefit of reducing the impact to the environment. As machines have grown in size, these engineering enhancements ensure equipment is being outfitted with technology that allows machines to operate as efficiently as possible.

One such enhancement is Volvo Construction Equipment’s new OptiShift technology. This driveline technology-standard on the L150G, L180G, L220G and L250G wheel loader models-is proven to increase fuel efficiency by up to 15 percent more than previous wheel loader technology, according to Doug Phillips, product competency manager for Volvo Construction Products, based in Shippensburg, Pa. In addition, competitive testing in short-cycle loading and level-uphill load-and-carry scenarios has proven significant reductions in overall fuel consumption-up to 30 percent less than similar size competing models-while lessening environmental impact.

The OptiShift transmission-a refinement of Volvo’s fuel-saving Automatic Power Shift (APS)-consists of a torque converter with lock-up and free wheel stator that also enlists the Volvo-patented Reverse By Braking (RBB) function. When operating at a constant speed, the pump and turbine rotor inside the torque converter are locked together through a direct-drive clutch, lowering power losses and fuel consumption. Auto lock-up occurs in second, third and fourth gear.

The RBB feature automatically applies the brake when the operator shifts between forward and reverse, and vice versa, instead of engaging the torque converter. Consequently, the reduced loading stress on the torque converter and transmission provides increased fuel efficiency and durability.

“When the computer sees these shifts being made, it applies the brakes,” Phillips says. “OptiShift automatically does what the operator had been used to doing, only faster and more efficiently.”

Phillips says Volvo is training operators on how to leverage engines to achieve higher torque at a lower rpm, which is an operational technique that also improves fuel efficiency. According to Phillips, many operators have a tendency to hold the fuel pedal to the floor for more power.

“We’re trying to show operators what we’ve designed and how it works so they can get the most out of it,” he says.



Tracking Savings

Another fuel-saving control feature is Automatic Traction Control (ATC), developed by Volvo for their articulated haulers. The ATC system includes a number of sensors that control the differential locks with signals to the electronic control unit (ECU). In normal mode, Phillips says ATC selects the fuel-saving 6x4 drive and only engages the 6x6 drive when operating conditions call for it. The sensors control the differential locks with signals to the machines’ ECU, and immediately sense even the slightest wheel slip, engaging the needed drive combination immediately.

Phillips says this translates into maximum productivity and reduces fuel consumption up to 6 percent. The ATC system also extends tire life and protects the driveline from unnecessary damage and wear.   

In addition to the ATC, Phillips says the Volvo CareTrack System also saves fuel. The system became standard in 2010 on all new Volvo articulated haulers (over 10 tons), articulated haulers, excavators (over 12 tons) and motor graders. According to Phillips, CareTrack is Volvo’s telematics system that allows a machine to communicate its performance data variables-via satellite-to a web portal where the equipment manager and dealer can access the machine’s internal diagnostics and performance. The system allows them to remotely track the usage, productivity and fuel consumption of articulated haulers.

CareTrack generates reports on how each machine is used, including operational information such as engine load and use of brakes and differential locks, Phillips says. Fuel usage and operational information-hours spent working versus idling versus traveling-are also tracked. The ability to collect this data allows equipment managers to establish benchmarks for the various operational categories for different types of machines in their fleet, and identify equipment and operators that produce the best results.

The use of telematics can also issue equipment warnings, for example, if the transmission is being misused or abused.

“On trucks for example, telematics can inform equipment managers if engines are operating beyond the most efficient speeds and rpms; or if retarders are being used to slow down trucks or burning off expensive brake pads,” Phillips says. “It doesn’t cost anything to engage a retarder pad, but every time an operator presses the brake pedal, it’s costing someone some money.”

Don Morgan, vice president of Morgan Contactors Inc., located in Clarkesville, Tenn., says CareTrack helps reduce the company’s downtime.

 “The system alerts us via email directly to critical personnel’s phones so they can respond immediately,” Morgan says. “A lot of times we will know of those alerts even before the operator does. The CareTrack System provides critical information about how productive a machine is operating-things like idle time, if the machine is stopped, when the machine is being turned on and off--things like that. It’s a very productive tool for our company and helps save fuel by allowing us to keep a watchful eye on all of that activity.”

Darren Capps, county engineer in Covington County, Ala., says he can attribute the increase in productivity of the county’s fleet of motor graders to CareTrack.

“There’s no wasted time, everything is 100 percent efficient, and we can also use it to analyze fuel consumption,” Capps says. “We probably save 1 gallon per hour, which adds up a good bit when one grader runs about nine hours per day. We have eight graders, so that adds up pretty quick.”



Engine Enhancements

Phillips says improvements to Volvo equipment engines can also provide fuel savings. The newest range of Volvo articulated haulers is equipped with Volvo D11 and D16 Interim Tier 4 engines that feature V-ACT (Advanced Combustion Technology). Phillips says these engines give the articulated haulers higher horsepower and higher torque than previous models-up to about 5 percent more horsepower and up to 20 percent more torque. Additionally, new crankcase ventilation in the engines helps to make for a cleaner environment by ensuring that no oil mist is present in the blow gasses, he says.

New high pressure fuel injection in the engines results in reduced fuel consumption because of a more efficient burn. The Volvo D11 and D16 Interim Tier 4 engines meet new regulation standards by reducing nitrogen oxide (NOx) emissions produced during combustion, he says. A new variable geometry turbocharger also promotes fuel efficiency. The turbocharger improves quick engine response and high torque at low and high engine speeds.

With the combination of these many fuel-efficient technologies-drivetrain, tracking and engines-Phillips says contractors can improve their bottom lines, all while making less of an impact on the environment.