Volvo Trucks has expanded its XE (referring to ‘exceptional efficiency’) powertrain package lineup with the introduction of the XE11 for its 11-liter Volvo D11 engine. Available on Volvo VNM and VNL models and rated up to 80,000 lb GCWR, it’s said to be ideal for LTL, , bulk haul, and other regional applications. The powertrain package improves fuel efficiency by up to 3%, Volvo says.
Volvo first introduced XE packages for its 13-liter D13 and 16-liter D16 engines, it says it’s been spec’d on more than 24% of all Volvo-powered trucks ordered in 2013.
The XE11 package starts with a D11 engine sporting 405 hp and 1550 lb ft. of torque, mated to a Volvo I-Shift overdrive transmission with a 0.78:1 ratio, plus axle ratios of 2.64 to 2.80. Proprietary software manages communication between these components.
Volvo says XE11 ensures that the engine runs in its sweet spot without wavering at any road speed. The I-Shift transmission and XE software control the engine to maintain rpm as low as 1150 while cruising at 65 mph.
The basic XE idea is to improve fuel efficiency by lowering engine rpm at a given vehicle speed, a concept Volvo calls “downspeeding.” XE allows the engine to cruise about 200 rpm less than the average truck. Fuel efficiency is said to improve by about 1.5% for every 100 rpm of downspeeding, so customers spec’ing the XE package can expect up to a 3% improvement when compared with another overdrive transmission in a similar operation, says Volvo.