Automotive

Freightliner SuperTruck shows other transport trucks how efficiency is done

Freightliner SuperTruck shows ...
The one-of-a-kind Freightliner SuperTruck
The one-of-a-kind Freightliner SuperTruck
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The one-of-a-kind Freightliner SuperTruck
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The one-of-a-kind Freightliner SuperTruck
The SuperTruck is reportedly 115 percent more freight-efficient than a baseline truck
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The SuperTruck is reportedly 115 percent more freight-efficient than a baseline truck
The SuperTruck's rooftop solar panels
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The SuperTruck's rooftop solar panels

Back in 2009, the US Department of Energy issued its SuperTruck Challenge. The program provided funding for truck manufacturers to design and build a prototype vehicle that was at least 50 percent more freight-efficient than a baseline 2009 truck. Daimler Trucks North America recently unveiled its response – the Freightliner SuperTruck. It goes beyond the 50 percent figure, with a claimed efficiency increase of 115 percent.

The truck was created through a collaboration between Daimler-owned companies Freightliner, Detroit Engines, Mercedes-Benz and Fuso.

Much of its increased efficiency is due to better aerodynamics. This was achieved partly through a very streamlined tractor that includes features such as adjustable ride height, rear wheel fairings, articulated side extenders that bridge the gap between tractor and trailer, and ventilation slats in the grille that close when the vehicle is traveling at highway speeds.

That streamlining proceeds back to the trailer, where side skirts channel air past the wheels and away from the underside, while rear fins keep turbulence from building up in the space behind the trailer. As a result, the SuperTruck is a claimed 54 percent more aerodynamic than the baseline truck.

The SuperTruck is reportedly 115 percent more freight-efficient than a baseline truck
The SuperTruck is reportedly 115 percent more freight-efficient than a baseline truck

A lot of emphasis was also placed on using lightweight materials, and reducing friction. This includes a tractor frame design that requires fewer crossmembers, a lighter rear suspension, and custom Michelin tires made with a rubber compound that decreases rolling resistance. Utilizing these approaches and others, a total of 700 lb (318 kg) was shaved off of the tractor.

Perhaps not surprisingly, the SuperTruck also has a hybrid diesel/electric drive system. As a means of boosting its battery power, however, it utilizes a waste heat recovery system which harvests thermal energy from the hot exhaust. The custom-designed low-friction 10.7-liter engine, meanwhile, manages an impressive 50 percent brake thermal efficiency (which was another stated goal of the SuperTruck Challenge).

Many other efficiency-boosting features were additionally incorporated. A few of these include rooftop solar panels on the trailer that can independently power its cargo-cooling system; an exhaust aftertreatment system that allows the engine to run at higher temperatures and pressures; and a GPS-based predictive system that shifts gears and adjusts speed, based on the upcoming terrain.

The SuperTruck's rooftop solar panels
The SuperTruck's rooftop solar panels

The 115-percent figure was arrived at based on a five-day, 312-mile (502-km) round trip route on Texas Interstate 35 between San Antonio and Dallas, at a weight of 65,000 lb (29,484-kg) GVWR (gross vehicle weight rating) and a speed of 65 mph (104 km/h). Its actual fuel efficiency on that trip was 12.2 mpg (19.3 L/100km), which is reportedly about twice what most trucks are able to attain under similar conditions.

For examples of other recent highly-efficient truck prototypes, check out the efforts from Walmart, Technical University Munich and Mercedes.

Source: Daimler via IEEE Spectrum

7 comments
Joel Detrow
All that is pretty impressive, but how much does this SuperTruck cost relative to a NormalTruck?
Germano Pecoraro
This design are only exsperimental, not Forder line production!
Don Duncan
Once again I remind everyone that figures like "700 lbs lighter" and "more aerodynamic" are meaningless. What is the curb weight and drag? But kudos for giving the mpg (12.2) at 65mph.
Mr. T
54 % more aerodynamic? NASA achieved that much way back in the 1970's . How about a mere 1% improvement in actual road going production vehicles?
Intellcity
With fuel surcharge. The more fuel costs per gallon, the better for the O/O once you get above the average MPG. There are truckers out there getting over 11 MPG but not going 65 MPH.
Tim Strom
I had a 38 ft diesel motorhome with the 400 HP Cummins engine and on that same route, with a steady speed of 62 MPH and towing a 4000# vehicle, we averaged nearly 10 MPG with a boxy shape and some strong sidewinds. A speed increase to only 65 MPH resulted in nearly a 10% decrease in fuel mileage. The new trucks are a huge leap in the right direction with the streamlining and computer controlled drivetrain but a small drop and some gearing changes might will result in more fuel savings. Just my .02 worth.
Parkour_rocks
They should also put regenerative braking systems on all of the axles. It would help save the physical brakes, and recover some electricity for the electric drive.