Volvo Truck Shows Off 16-Liter Diesel

By Tom Berg, Truck Editor | September 28, 2010

The D16C powers Volvo's new, smooth and quiet FH16 cab-over engine model, which is built as a truck or tractor. Heavy equipment haulers are one target market for the Big Power FH in Europe, the Mideast and South America.
The D16C features rear gear train for quietness, and allows fitting of a powerful rear power take-off. For Europe, it's rated at 550 and 610 horsepower, and would make similar power if and when it's sent to North America for use in Volvo and maybe Mack trucks.

Volvo Truck Corp. of Sweden has unveiled a new high-horsepower 16-liter diesel that could appear under the hoods of American-made Volvo and Mack trucks. The D16C powers a new FH16 cab-over-engine vehicle that is now Volvo's top model in Europe and other world markets.

The D16C is rated at 550 and 610 horsepower for European-spec trucks, and would make similar power if sent to the United States, Volvo product planners indicated. Its high power and torque—1,845 pounds-feet for the 550-hp rating and 2,065 for the 610—will boost productivity for high-gross-weight rigs common in Europe. If sent here, the D16C could find buyers among heavy haulers, and performance-minded fleets and owner-operators running construction and over-the-road rigs.

The D16C could serve as Volvo Truck North America's flagship engine, and would be the biggest diesel in a new family of Volvo-Mack engines due out by 2007. Emissions limits in January '07 will be too tight for Volvo's current D12 and Mack's 12-liter models. The sister companies have said that newly designed engines sharing common architectures will be built in Hagerstown, Md. If the D16C becomes part of that family, it would be built initially, and perhaps solely, in Sweden, as now.

The D16C would use higher fuel pressures and exhaust-gas recirculation if sent to the States before '07, said Lennart Langervik, D16 program manager at Volvo's Gothenburg headquarters. With these it would meet current October '02/January '04 exhaust emissions limits. He wouldn't say if the EGR would be the V-Pulse system fitted to Volvo's D12 that is now sold in the U.S. and Canada, or if it would use a selective catalytic reduction (SCR) system in '07 and later.

Volvo people would say little about the engine's possible North American role, and declined to discuss how it would affect the Cummins ISX, which is now the largest diesel offered in Volvo and Mack trucks. Langervik did say the D16C would fit in Volvo's VN conventional, so it should also go in the VHD vocational truck.

The inline-six-cylinder D16C replaces Volvo's current D16, which tops out at 460 horsepower, and shares only the older engine's bore and stroke dimensions and a few minor parts, Langervik said. The new engine has a high-pressure fuel system with twin-solenoid unit injectors controlled by advanced electronics.

Valves are run by an overhead cam and timed by rear-mounted gears—a design that cuts weight, lowers noise, and allows installation of a rear-mounted power take-off. The rear gear train also results in a narrow front profile, which enhances underhood airflow to aid cooling. An optional engine brake makes up to 510 horsepower to retard the truck on downgrades.

The D16C's ability to move heavy trucks was evident as I joined trade press reporters from eastern Europe, the Mideast and North America for some seat time in new FH16s cabovers. This was during their unveiling at Kramfors, in Sweden's west-central High Coast region.

I drove five rigs with both 550- and 610-hp ratings of the engine. Three rigs were long, seven-axle 125,000-pound truck-trailers, and two were five-axle 84,000-pound tractor-trailers. Like my colleagues, I was impressed with the 16-liter diesel's unassuming muscle. Mated to smooth-acting clutches and easy-shifting 14-speed synchromesh transmissions, the engines started the trucks easily and propelled them ably over sometimes hilly terrain.

Of course, it takes horsepower to keep up road speed on steeper hills, so some downshifting was needed, but less than what would've been required with lesser engines. And the synchro trannies made the work easier.

Each engine's high power and torque were masked by the smoothness of the highly refined FH cab and chassis. There was absolutely no vibration, even at full throttle in the engine's 1,000- to 1,400-rpm torque peak, where 1,800 pounds-feet or more of torque were sent into the driveline.

The trucks were almost eerily quiet and engines only whispered, even at higher revs with the strong retarders engaged. It's almost a pity that the FHs aren't offered in the States, but they wouldn't sell in a market that prefers conventionals.

Aiding the quietness was the engine's position in the frame, to the driver's side and rear. Many possible sources of engine noise, including the rear-mounted gear train, are therefore behind the driver. Whether the D16C would be as quiet in a Volvo VN, with the engine's rear and its timing gears near the driver's right foot, won't be known until one is installed in those chassis.

In a VN or perhaps a Mack CL, the D16C would make the same sales argument as Big Power diesels from domestic builders: High horsepower and hefty torque are not only pleasing to drive, but also boost productivity by keeping the rig moving on steep upgrades at brisk speeds.