Very high tech in a plain, white wrapper
What you can see of Volvo’s SuperTruck vehicle is pretty spectacular, though fairly plain at heart. It’s what you can’t see that stirs the imagination.
One gets a lot of stares when driving a truck like this. There’s no way not to notice the double-takes when cars pass the SuperTruck on the freeway. It’s not that unusual from behind, with its trailer-tail, but the full-length and full-height side-skirts get looks, especially from other truck drivers. But the heads really ratchet around when other drivers come around front and see the dramatically shaped hood and very sexy fender/headlight/grille assembly.
I recently spent a day driving Volvo’s SuperTruck, along with Jack Roberts of Heavy Duty Trucking. We were the first to journalists ever to drive the truck. It wasn’t a test drive in the conventional sense where I check out steering and braking and cab noise and driver comforts, etc. This drive was about experiencing the technology first hand, and getting a glimpse of what we could be driving 5-10 years from now.
The dashboard, driver area and sleeper interior are stock VNL 780, save for a few control devices wired into the dash for the engineers’ convenience rather than appearance. Our tour guide, Keith Brantley, senior project manager for the complete vehicle, told me the design team so no point in revamping the interior because it would not contribute to the goals of the project.
The exterior of the cab, however, has been completely redesigned. It’s 3 inches taller and 8 inches longer than a standard VNL and wider at the back than the front. The roof line is quite different because designers optimized the frontal profile of the truck for aero drag reduction.
The windshield is custom-built and highly raked and curved for optimum aerodynamics. The hood is severely sloped too. From the driver’s seat, the hood was invisible. It’s was like driving a cab-over.
Overall it’s rather plain looking, but then so is a raindrop, which is supposed to be the ideal aerodynamic shape.
Beneath that fairly plain white skin is about $2 million worth of technology and many one-of-a-kind, hand-made prototype parts.
I want to make one thing abundantly clear, and this is a point apparently lost on many of the internet trolls that have dismissed this truck as ugly and wholly impractical. This truck is a rolling laboratory, a technology test-bed, a mobile proving ground, if you will. It’s not available for sale and it never will be. It looks like it does in order to meet the criteria and the performance targets set by the U.S. Department of Energy to demonstrate technology that could lead to improvements in freight efficiency and reductions in greenhouse gas emissions (reduced fuel consumption) in future truck designs.
The folks who designed the truck are fully aware that the trailer skirts, as they are, would never pass muster with fleets worried about the potential for damage or limited access to the undercarriage. The designers were not trying to sell fleets on the idea of full-length and full-height skirts; their goal was to prove that a Class 8 tractor trailer loaded to 65,000 pounds (29,500 kg) — the U.S. DOT-acknowledged average weight of a loaded tractor-trailer in that country — could do its job at an astonishing 12-13 miles per gallon. That’s double the fuel economy of some trucks operating under similar conditions today.
So, yes, some elements of the design are impractical now. But if the day comes when fuel tops 5 bucks a gallon, some clever engineer will make the full-height skirts retractable and more practical for fleet use.
Because of all that aero cladding and rolling-resistance reduction, the truck requires 35% less horsepower (120 hp vs. 188) than the baseline 2014 Volvo VNL to stay rolling at 65 mph on flat ground. There’s an 11-liter, D11 engine under the hood producing 425 horsepower and an amazing (for the displacement) 1,700 pound-feet of torque. The engine features common-rail fuel injection, the new “wave” piston design, a newly designed cooling package and fan shroud, low-viscosity oils and turbo-compounding.
Again, the trolls say the truck would never work in the mountains, and they are correct. It wasn’t designed for that. The substantial torque is to facilitate downspeeding. It works great on rolling interstate-type hills, but maybe not so great when climbing mountains.
To keep weight down, Volvo used a 6×2 drive axle and many lightweight components including a custom-designed frame made almost entirely of aluminum, which saved more than 900 pounds. The roof, hood and side fairings are made of carbon fiber. While durable and light, like the frame, they are too expensive for the current market. Engineers carved away more than 5,000 pounds from the baseline truck before adding about 1,200 pounds of new equipment and aero devices. In the end, they achieving a net weight reduction of 3,200 pounds compared to the baseline truck and trailer.
So what’s it like to drive? It’s a bit nerve-wracking messing with traffic on a public highway in a virtually irreplaceable truck that’s worth more than $2 million. Having said that, it’s not all that different from any other VNL I’ve driven in the past five years.
The most obvious difference is the lack of wind noise. That’s a testament to the job designers did helping it slip through the air. Most surprising, but I have experienced this earlier with the Cummins/Peterbilt SuperTruck, was how fast it takes off on a downhill grade owing to the lower mechanical rolling resistance and the massive reduction in aerodynamic drag. It feels like you’re pouring on the power, but the driver display reveals the truck is in neutral and idling at 700 rpm. There’s very little holding this truck back at highway speed.
For obvious reasons, Volvo’s marketing department hasn’t named any of this powertrain technology yet. Brantley was reluctant to relate the SuperTruck’s predictive cruise control system to Volvo’s currently available I-See system, so I have to assume it was not I-See or even an advanced version of it. However, the system does use GPS terrain maps, a look-ahead feature and some really interesting fuel mapping and shifting strategies to achieve optimum power for the terrain.
Brantley told me the engine will produce 1,700 pound-feet of torque from 900-1,300 rpm. He also noted that there’s still plenty of grunt at 800. With a 2.47:1 axle ratio and an overdrive I-Shift transmission, the truck cruises at 65 mph at 1,050 rpm. That’s fairly low on the torque curve, so when approaching a hill, the truck frequently downshifted to 11th gear at about 1,300 (top of the peak-torque range) and strolled up the hill at maximum torque and minimum fuel consumption.
It also gave up a few miles-per-hour on the upgrade, knowing in advance that it would make up the loss when coasting down the other side. The controllers backed off the throttle close to the top of the hill, and sometimes — not always, which surprised me — dropped into neutral. Brantley assured me the system was functioning as designed.
All I could conclude from pattern was that the system saw some savings opportunity that I didn’t. If it were up to me, I would have shifted to neutral but instead the truck stayed in gear some of the time, and readied us for the next hill. It’s clearly smarter than I am. And that’s half the battle with this new technology.
If drivers are to take full advantage of it, they really should let the truck do its thing. Many, however, don’t like the idea of giving up a little road speed when climbing a hill in order to ease the load on the engine. That’s were a good chunk of the fuel savings come, I think.
There’s more to say about driving the truck, but I’ll save that for a future blog. One of the features of the truck is a new sort of charging system that engages a pair of 250-amp, 24-volt alternators to charge a bank of three lithium-ion batteries. There are huge advantages to this, but the cost of the batteries will likely remain a barrier to commercialization for some time.
The other interesting feature is the electronic mirror system. I have some strong opinions here, and I want to stress that I’m not holding Volvo’s system up as an example. It’s the first such system I have ever used, and it was, in Brantley’s words, jerry-rigged. So, my criticisms of the system are more conceptual than practical. In short, the electronic mirrors (displays mounted on the A-pillar) worked fine on the highway for lane changes and the like, but were nearly useless for precision maneuvering in reverse.
The fuel economy people see exterior mirrors as a 2-3% threat to fuel efficiency. I see electronic mirrors as a huge threat to safety. I’ll have more to say on the matter shortly.
I’ll leave you with this to ponder. The goal of the entire American SuperTruck project is to build vehicle prototypes that push out the boundaries of both fuel and freight efficiency to levels beyond where today’s OEM R&D budgets would normally let them go. The various SuperTrucks are concept vehicles, science projects if you will, that pull forward ideas and technologies that in the normal course of vehicle development might languish on bottom shelves and on computer hard drives and likely never see the light of day because the ROI for the developers just isn’t there.
Volvo has proven with this project, and Daimler too, to be fair, that an 11-liter engine works just fine in most line-haul, truckload applications with gross weights below 80,000 pounds. We have already proved here, on the north side of the border, that 13-liter engines do just fine pulling Super-B trains in many, many applications. This downsizing of the powertrain opens doors to huge fuel savings, and along with the highly advanced power management strategies we’re seeing from Volvo’s and other OEs’ SuperTruck projects, I think the truck of the future will be quite different in many ways from what we’re driving today, even if they don’t look that different.
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