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.”