Trucks use an awful lot more fuel than cars. Consequently, the fuel you can save from making small improvements can be massive.

That’s what Bob Sliwa aims to do when he sets out from San Diego, Calif., on May 17 in his Shell Airflow Starship record truck.

Hauling his full-sized trailer fully loaded to the truck's 80,000 pounds capacity, he aims to set the fuel economy record for a loaded Class 8 truck in a six-day cross-country trip to Jacksonville, Fla.

There has been a lot of effort recently to build electric semi trucks, including those from Nikola, Tesla, Daimler, Thor, and others. Electric trucks, however, are designed more for short-haul operations rather than cross-country trips, says Mike Roeth, executive director  of the North American Council for Freight Efficiency (NACFE), which is sponsoring Sliwa's record run. NACFE is a spinoff from the Rocky Mountain Institute, which aims to scale up promising technology to improve efficiency in all kinds of life endeavors.

The Starship uses diesel power, but is optimized for efficiency.

Where modern trucks use trailer skirts and tails to minimize drag, the Starship is covered in fairings, with skirts covering both the trailer axles and the drive axles of the cab, grille shutters, and a boat tail on the back of the trailer. The cab has been completely reconstructed from carbon fiber with a new aerodynamic profile.

It uses hybrid axles to give the truck a boost up hills despite taller gearing for more efficient highway cruising.

The top of the trailer is covered by a 5,000-watt array of solar panels which charge batteries to provide house power for the sleeper cab when Sliwa has to stop. (He will still be subject to standard trucking rules including limit on his daily hours driving and mandatory rest. So this record run won’t be a race.)

Sliwa aims to improve on the state of the art of about 10.1 mpg, says Roeth. The national average for semi trucks is about 7 mpg, while fully loaded trucks get less than that. 

NACFE is a spinoff from the Rocky Mountain Institute, which aims to scale up promising technology to improve efficiency in all kinds of life endeavors.

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Roeth, whose organization is promoting the event, couldn’t give us a target the Starship is shooting for, in part because the organization will measure Starship’s freight-ton efficiency—measured in ton-mpg—rather than straight mpg. After all, what use is driving a 10-mpg truck if its not hauling freight.

The Starship will be loaded with nearly 50,000 pounds of cleaned reef materials on its way to the East Coast.

Sliwa has been driving trucks since the 1970s oil crisis first hit. Semi-truck fuel economy has been a make-or-break financial interest for him his whole career. He has a fully equipped shop in New Britain Connecticut where he builds the trucks. This will be his third record attempt, following the Bullet Truck of his own design in 2009, and an entry in the DOE’s Supertruck 1 program in 2010.

Robert 'Bob' Sliwa behind the wheel of the Shell Airflow Starship fuel economy record truck

Robert 'Bob' Sliwa behind the wheel of the Shell Airflow Starship fuel economy record truck

The Starship is also sponsored by the DOE as part of its Supertruck 2 competition, which began in 2016.

Sliwa will travel mostly across Interstate 10 on the record run to avoid the worst of bad weather and bad highways.

Every new technology, of course, comes with tradeoffs. We asked Roeth what features of the Starship he sees that might hold up commercialization of its technologies.

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Beyond the cost of the carbon fiber cab, he noted that it may not be as maneuverable with the full fairings extending from the back of the cab to the bed, that it doesn’t have the ground clearance over less-than-flat roads that most trucks do, and that it may not be as resilient against road debris as contemporary trucks.

After all, the Starship is optimized for a single long, highway trip, not for maneuvering in and out of loading docks in cities.

NACFE will gather full telemetric data from Starship and Sliwa along their drive, including fuel usage, throttle, speed, and braking, and plans to publish the data on June 6. We’ll do our best to follow along and let you know their progress toward improving freight efficiency in the U.S.