Volvo Trucks announced its Greenhouse Gas 2014-certified engines are providing greater fuel efficiency than anticipated. The integrated engines are delivering up to a 3% fuel efficiency improvement compared with their 2013 counterparts, according to the company.

“We remain focused on ensuring that the ongoing phases of engine and vehicle regulations do not burden our customers, but instead create value for their operations,” said Gor̈ an Nyberg, president, Volvo Trucks North American sales & marketing.

A combination of in-lab and on-road testing proved that the initially announced fuel efficiency figures of up to 2% understated the true fuel savings and value of 2014 Volvo engines.

Refinements and design changes contributing to fuel efficiency improvements in Volvo’s 2014 D11, D13 and D16 engines include:

• Low-friction cylinder improvements, including a redesigned piston, liner and oil scraper ring developed with smoother surfaces;
• A clutched air compressor, which reduces engine load by completely disengaging the clutch from the engine when not in use;
• Advanced combustion technology of a new seven-hole injector, which offers better fuel atomization for a more even distribution of fuel within the cylinder, maximizing fuel efficiency and offering a greater savings for customers; and
• An improved crankcase ventilation system, which filters more oil from blow by gases before they leave the engine and at the same time improves engine back pressure for better performance.

Along with fuel efficiency improvements, a two-piece valve cover on the D13 engine improves serviceability, which reduces repair time and is easier to handle than previous covers. Volvo also removed lead from the valve- train of its 2014 engines to reduce its environmental impact.

In addition Volvo Trucks’ XE powertrain package boosts fuel efficiency by up to an additional 3%. Available on Volvo VNM and VNL models equipped with 2014 Volvo engines, the XE11, XE13 and XE16 packages improve fuel efficiency by lowering engine RPM at a given vehicle speed, a concept Volvo calls “downspeeding.”

Fuel efficiency improves by about 1.5% for every 100 RPM of down- speeding, so customers spec’ing the XE package can expect up to a 3% improvement when compared with another overdrive transmission in a similar operation.