Volvo Trucks’ 2017-model engines will include more efficient fuel and combustion systems and, in one model, turbo compounding to add power, responsiveness and fuel economy, officials said Tuesday at a press event at Volvo Group’s powertrain plant in Hagerstown, Md.

They also described a compact One Box exhaust aftertreatment system and an improved I-Shift automated manual transmission with optional crawler gears for heavy hauling and severe vocational service. The products will be phased into production at the plant starting this fall and into next year.

Engines will include refined D11 and D13 diesels and a previously improved D16, said Wade Long, product marketing director. The 10.8-liter D11 will get a top rating of 425 hp, up from the current 405 hp. The 12.8-liter D13's 455-hp rating will add 100 lb-ft, going to 1,850 lb-ft.

A turbo compounded D13 TC will have a second turbocharger linked via fluid coupling and a geartrain to the crankshaft, grabbing otherwise wasted energy from the exhaust to gain as much as 50 hp and 4% in fuel economy. It’s designed for long-hauling at steady highway speeds, mostly 65 mph, he said. So the TC will be offered on sleeper-cab VN models when it becomes available in mid 2017.

The new D11 goes into production in January, while the improved D13 will enter production in October. The D11 will deliver 2.2% better fuel economy than the current model, while the D13 gains 2.5%. Adding turbo compounding’s 4% gain means the D13 TC will be as much as 6.5% better in highway service.

When spec’d with Volvo’s XE (for eXceptional Efficiency) “downspeeding” package and a 2.47 rear axle ratio, a D13 TC will cruise as low as 1,050 rpm in top gear at 65 mph, Long said.  XE includes Volvo’s I-Shift automated transmission.

Pricing was not disclosed, but an investment in the TC option will pay off in about 18 months, other officials said.

The 2017 D11 and D13 feature a “new wave” piston that increases the compression ratio to 17 to 1 (from 16 to 1) for better fuel efficiency. Improved flame propogation and combustion reduces soot, while pistons are treated to lower friction between them and cylinder walls. A common-rail fuel system is packaged under the new split valve cover for protection and easier servicing.

One Box, I-Shift

The One Box aftertreatment system weighs less and is 12 inches shorter than the current “teapot” system, so takes less frame space. The diesel particulate filter’s substrate can be more quickly removed for cleaning or replacement.

I-Shift for 2017 gets new hardware and software, and its clutch has larger dampening springs to better absorb torsional vibrations and improve the clutch's overall durability. A new I-See system enables predictive cruise control for more efficient hill climbing and descending. I-See uses sensors and GPS positioning to recognize previously traveled routes to help manage the throttle, engagement of EcoCoast freewheeling and use of the engine brake.

The I-Shift's optional crawler gears add one or two low-low ratios to aid starting on upgrades for heavy combination vehicles and vocational trucks, making the 12-speed transmission into 13- or 14-speed gearboxes, Long said. The 13’s crawler ratio is 17.54 to 1 and the 14’s are 19.38 to 1 and 32 to 1.

The gears are contained in a back section just ahead of the bell housing. The crawler-gear section adds 5 inches to length and 90 pounds to a 12-speed I-Shift’s 720 pound weight.

Gears and other hardware have been hardened to withstand frequent shifting under harsh conditions. Concrete mixer trucks which have to creep while pouring curbs are among the vocations suitable for the crawler gear-equipped I-Shift, “and we’re ready to attack the vocational market,” Long commented.

Current I-Shifts now go into nearly 83% of Volvo trucks, mostly highway tractors, said Gӧran Nyberg, president of Volvo Trucks North America, who was at the press event. Volvo diesels go into almost 93%.

“The success of Volvo’s proprietary powertrain components is a direct result of the Hagerstown facility and its distinctive combination of powertrain engineering and manufacturing in one campus,” said. “These unique capabilities had a significant impact on the development of our updated 2017 powertrain, which will no doubt further our leadership in integrated powertrain technology.”