I recently took an XE13-equipped Volvo VN 670 tractor on a six-hour road test, highlighted by a climb up Fancy Gap, a 2,000-foot mountain on I-77 near the North Carolina-Virginia border.
For most of the run up the mountain, I was able to hang out in the middle lane, easily passing lugging rigs, some of which were sporting the logos of much higher displacement engines on their hoods.
That’s the beauty of the XE13’s new technology: because the drivetrain is fully integrated, each system knows precisely what demands are being placed on each component. This information is updated thousands of times per second — and the decision-making process never stops. In essence, this light-speed communication network allows the tractor’s I-Shift transmission to direct the engine to respond to its needs instead of the other way around.
The result is an amazingly smooth ride up and down a mountain in crowded road conditions, while pulling 77,000 pounds. There is no tentative gear-searching going on here. The XE system tunes overall vehicle performance to match an array of driving conditions and then provides continuous, intelligent power to consistently meet and overcome those conditions.
In my case going up Fancy Gap, the system selected 10th gear early in the climb and held a steady 53 mph all the way up the summit, never straining and never feeling like the transmission was winding out.
The XE13, a combination of Volvo’s I-Shift automated-manual transmission Volvo engine with modified-software, allows the engine to cruise at 1150 rpm at 65 mph.
The XE13 package is rated for up to 80,000 pounds and includes a 425-hp, 1750 lb.-ft.-torque D13 engine. The Volvo I-Shift overdrive transmission comes with a 0.78:1 ratio and a software package that facilitates communication between the integrated powertrain components.
The XE13 package is a plus on long, straight, flat roads as well. In cruise mode, the optimized powertrain runs at significantly lower rpm than a conventional unit. The result is a much more fuel efficient vehicle.
At 65 mph, my Volvo’s DD13 was logging 1,150 rpm — good enough for a net fuel economy boost of around 3 percent compared to conventional powertrains. Volvo engineers note that every 100 rpm reduction in an on-highway diesel engine nets a 1.5 percent fuel savings. Volvo is confident in predicting fuel savings of up to $2,000 a year for each XE13-equipped VN tractor.
Affected trucks include model year 2008-2018 Freightliner Cascadia and Western Star 4700, 4900, 5700 and 6900 trucks. DTNA says after hard brake applications, the brake light pressure switch may not activate the brake lights with the light application of the brake pedal.