Designed for the future
The scale of Starship's challenge has attracted support from a wide range of industry suppliers, all eager to prove their products can help the world in its transition to a lower-carbon future.
The truck's features include "low-rolling resistance" tyres that are designed to reduce friction with the road and a six-cylinder diesel engine that demonstrates its superior fuel economy.
The roof of the Starship Initiative has a 5,000-watt solar panel, providing electricity that powers the vehicle's air conditioning and much of its interior. The truck also showcases Shell's lubricants products that are specially formulated to reduce energy loss through friction in the engine.
For Sliwa, though, the body design is the biggest point of pride. Through his business, AirFlow Truck Company, he crafted Starship's convex windshield, and helped to modify its "boat tail", which is an aerodynamic device attached to the rear of a truck to prevent the vacuum of air (drag that Sliwa likens to a parachute).
"The front has to work in harmony with the rear," explains Sliwa. "When we design everything from scratch, we can get rid of all these constraints and try to build the most hyper-aerodynamic model possible."
Sliwa's cross-country drive began in San Diego, California, where 39,000 pounds (18,000 kilograms) of reclaimed concrete boulders were loaded into the Starship trailer to emulate the kind of weights of truck cargo.
The truck arrived in Jacksonville, Florida on May 24. The cargo it carried is set to be combined with 3,600 tonnes of additional concrete boulders. It will be used to build a new artificial barrier reef offshore, forming a future habitat for marine life.
Along the way, Sliwa has been carefully monitoring computer terminals in the truck's cab, which resembles the cockpit of an aeroplane. He has been driving strategically, speeding up before hills to build momentum, while letting the engine idle during descent.
The vehicle is closely followed by analysts from a non-profit organisation, the North American Council for Freight Efficiency (NACFE), to ensure the test is conducted according to the protocol.
"We're pulling metrics off the truck, looking at the driving conditions - the elevation changes, the truck's speed, the wind resistance," says Mike Roeth, NACFE's Executive Director.
Since the aim of the trucking industry is to haul cargo, NACFE encourages all trucks to measure themselves according to freight-ton efficiency: how much weight they can carry relative to the amount of fuel.
"Trucking industry improvements are primarily driven by economics," says Roeth. "Besides the cost of fuel, truck manufacturers are also looking at fuel economy regulations governments are imposing, and they're going to need to build more efficient trucks in the future."
NACFE estimates that the average North American truck records roughly 72 tonne-miles per gallon – that is, the distance a weight can be moved on a single gallon of petrol. On completion of its cross-country journey, Starship recorded over 178 tonne-miles per gallon, which experts say is a near 248% improvement over the average North American truck.
Those improvements prove even more significant if multiplied by the number of heavy-duty trucks on the road. In the USA alone, if all trucks were as efficient as Starship, experts believe it could reduce annual carbon dioxide emissions by 208 million tonnes.
But the Starship Initiative is not a prototype for a new fleet of energy-efficient trucks. Rather, Shell sees the project as a way of starting conversations about how trucks can be more fuel efficient and therefore reduce their carbon impact.
For Sliwa, road trips have been made more bearable thanks to Kayla, the German shepherd dog he calls his "constant companion". But the hours on the road remind him why he first retired from truck driving in 1986: his passion was always designing and building trucks, not driving them.
"This is the last trip for us," he says. "After this we're retiring - and this time it's for good."