I couldn’t believe it was possible
to save 6.5% fuel.

When Volvo Trucks engineers first told John Moore that the new D13 with Turbo Compound engine was going to increase fuel efficiency by 6.5%, he didn’t believe it. “That’s a huge number. I said, ‘You’re going to have to prove that to me,’” Moore says. “Getting 6.5% out of anything today is just phenomenal.”

The engineers proved it — in fact, Moore now thinks, 6.5% may be a conservative number. Furthermore, aerodynamics and other improvements will add another percent, raising total fuel savings to 7.5%.

“The new D13 Turbo Compound is a truly unique engine,” Moore says as he walks the floor of the Hagerstown, Md., factory where all Volvo Trucks engines are built. “The D13 Turbo Compound is the only engine in the industry that uses a waste heat recovery system to save fuel by capturing lost energy.”


Typically when a gallon of diesel fuel is burned, half of the BTUs are wasted. The D13 with Turbo Compound funnels waste heat through a turbo compound nozzle and turbine. The turbine connects to a gear that brings power to the flywheel, converting exhaust gas energy into mechanical energy.

The result? Up to 50 extra horsepower.

“The D13 picked up 1850 rating on 450 hp. That extra 100 pound-feet of torque puts us at the top of the class,” says Brett Pope, senior product manager.

A split torque package lets the engine run in economy or performance mode. Because it’s integrated, the engine responds automatically. “As a driver, you just drive,” Pope says. “The engine responds automatically. And you get fuel economy savings and more power.”

"It's a truly unique engine"

Little tweaks for big savings “We just keep finding more things to perfect to get the load off and decrease friction in the engine,” Moore says.

A new wave piston, found only in Volvo engines, burns fuel more efficiently at higher compressions. A new two-speed coolant pump reduces load on the engine as its moving down the highway.

A unique twist on a common rail fuel injection system also lets the engine run much more quietly and smoothly. “It’s amazing,” Moore says. “Drivers are going to feel a noticeable difference.”

Engine - transmission teamwork More savings come from unique engine, transmission and axle configurations like the XE package. Reducing engine cruise speed by 100 rpm saves between 1% to 1.5% in fuel efficiency.

With turbo compounding, drivers will be able to reduce their engine cruise speeds on the highway to 1050 rpm. In states and provinces with 55 mph speed limits, drivers can run at a lower rpm and stay in top gear.

“Also, the turbo compounding engine is more efficient at lower rpms,” Moore says. “We have an engine saving fuel and a turbo compound unit maximizing efficiency with peak torque. It’s a win-win situation for fuel efficiency and performance.”

Engine Highlights

Wave Piston

Catching the wave

A new patented piston design uses a wave-shaped tab inside the piston. The injector sprays fuel directly onto the tab, which deflects the fuel back to the center of the cylinder for a cleaner burn. The wave tab eliminates wet spots on the cylinder walls and reduces soot. “Engineers in Hagerstown found a 90% reduction in soot because of this piston,” says Brett Pope.

Common Rail Fuel Delivery

Special delivery

A common rail fuel delivery system allows for an assembled camshaft, which saves 21 pounds of weight. Common rail also allows the engine to run more smoothly, cutting noise and vibrations to the cab. The results? A noticeably quieter engine, fuel savings, less wear and tear on the camshaft and longer engine life—plus calmer, more relaxed drivers.

Torque Packages

Just the torque you need

Engine software senses load weight, throttle inputs and roadway and automatically responds for more performance. It drops back into economy mode when less torque is needed. Unlike competitors, Volvo Trucks engines deliver split torque packages in a number of different combinations, with shift points in more gears.