A new video from Overdrive sister publication CCJ shows some of the time our colleague Jason Cannon got to spend recently with Alpha Drivers Testing and Consulting's Joel Morrow, who detailed his "Purple Haze 2" next-gen Volvo VNL860 he and partners have spec'd for maximum fuel economy.
Details on those specs? They're right here on the paired van trailer's side. It's Volvo's I-Torque spec for a D13TC (for "Turbo Compound") engine equipped with a 500-hp/1,950 lb.-ft. rating, the automated-manual 13-speed I-Shift transmission, and that low axle ratio of 2.16.
If the truck's Purple Haze moniker is familiar, you might well recall Overdrive 2024 Trucker of the Year contender and Morrow business partner Alec Costerus, managing the Alpha Drivers Transportation small fleet that's part of the pair's businesses launched together.
Costerus has been an occasional Overdrive contributor. In 2024 in the depths of the freight and rates doldrums (in some ways extending to the current moment), he authored this story in part about the spec of the original Purple Haze. It was an argument for the real ability of, and necessity for, owner-operators to set aside old pre-conceived notions about equipment spec and operational considerations toward a goal of maximum efficiency.
[Related: In a tough trucking-business environment, owner-operators must improve efficiency to compete]
Joel Morrow
For owner-operators, improving fuel mileage once depended in large part on speed, Morrow said. In order to maximize fuel economy, "you were driving 55 miles an hour."
Yet the powertrain in the Purple Haze 2 VNL860 is "aggressively downsped," he added, meaning it can achieve higher torque levels at lower rpms. "And so at 65 miles an hour, we're running about 900 rpm. And it'll hoof 80,000 pounds right down the road with no problem at 900 rpm."
That doesn't by itself guarantee what Morrow's achieving with this particular VNL -- 11 mpg and higher -- as Cannon points out in the video. The adaptive gearing in the I-Torque system helps, too. Check out the video for Morrow's walk through the unit, including lift axles on both truck and trailer and when and how he's able to use them:
On the push to 12 mpg, Morrow's planned a further reduction in rear ratio. "I think I'm going to push that rear axle ratio down to 2.05, and I think that not only is the engine going to turn 35 or 40 less rpm than the 2.16, but it's going to enable us to pick up some more of that kinetic energy, that 'free money,'" as he put it, "while we're going down the road where the truck will roll."
Best guess, he figures: 0.3 to 0.5 mpg better than where their current VNL860 will top out.
[Related: Trucker of the Month reaps 10-mpg-plus rewards of two decades learning, growing]
