Volvo Trucks North America has rolled out a new powertrain package—the XE13 (XE standing for “exceptional efficiency”) –that the OEM states will further reduce fuel consumption on its VN Series highway tractors.

Via what Volvo Trucks terms “downspeeding,” Volvo’s I-Shift automated manual transmission and a Volvo engine with modified software “allows the engine to cruise at just 1,150 rpm at 65 mph – about 200 rpm less than the average truck sold today.”

“Historically, we’ve seen a slow progression toward a lower ‘sweet spot,’ with the 1,300 to 1,500 rpm range as the current industry standard,” Ed Saxman, product manager – powertrain, said. “The engine with the XE13 package has a sweet spot of 1,050 to 1,500 rpm. Customers gain about a 1.5% fuel efficiency improvement for every 100 rpm of ‘downspeeding,’ so fleets that spec XE13 can expect up to a 3% improvement when compared to another overdrive transmission in a similar operation.”

The XE13 package is rated up to 80,000-lbs GCW and includes the following components:

  • Volvo D13 engine with 425 hp and 1750 lb-ft of torque
  • Volvo I-Shift overdrive transmission with 0.78:1 ratio
  • Axle ratios of 2.64 to 2.69
  • Proprietary software that ”facilitates seamless communication” between Volvo’s integrated powertrain components

“With the new package, the engine runs in its sweet spot at any given speed, never straying from its sweet spot at any point from zero through top speed,” Saxman said.

“When cruising at speeds below 60 mph,” he continued, ”the intelligent software is designed to prompt the I-Shift transmission to downshift only when necessary for maximum fuel efficiency. Like the song says, the I-Shift software knows when to hold ’em and knows when to fold ’em.”

“Any fleet focused on spec’ing their trucks for maximum fuel efficiency can benefit from the XE13 package, but fleets spending considerable time cruising at highway speeds will see the greatest improvements,” noted Ron Huibers, senior vp– sales & marketing. “Our intelligent, integrated XE13 package delivers improved fuel efficiency without sacrificing drivability during steep mountain inclines or stop-and-go traffic.”

Volvo Trucks regards the new powertain package as the latest step in fuel efficiency for Volvo customers, which the OEM said are already achieving up to 8% improvements in fuel efficiency over EPA ’07 engines. In November 2009, the OEM noted, the launch of its EPA ’10-certified ”No Regen” engines with SCR technology gave customers a 5% increase and powertrain enhancements and advanced aerodynamics, announced at the 2011 Mid America Trucking Show, add up to an additional 3%.