The Shell Starship's customized carbon-fiber cab and full side skirts along the length of the trailer, Cummins X-15 Efficiency engine, Bridgestone’s low rolling resistance tires, and smart driving strategy all contribute to the result of 178.4 ton-mpg for freight ton efficiency (FTE)—a nearly 248% improvement over the North America average. (image: Jennifer Shuttleworth)

Shell’s Starship fuel-efficient Class 8 concept truck delivers

Dubbed the Starship Initiative, the collaboration between Shell and Airflow Truck Co. on the Starship Class 8 concept truck achieved a 178.4 ton-mpg for freight ton efficiency (FTE) in a recent cross-country drive, which is a nearly 248% improvement over the North America average FTE of 72 ton-mpg for trucks.

The project culminated with the truck’s six-day 2300-mi (3700-km) coast-to-coast test drive that ended at its destination of Jacksonville, Fla., in late May 2018.  

The Shell Starship project began about four years ago when several Shell employees had an idea for a hyper-aerodynamic fuel-efficient Class 8 truck. (See “Shell, Airflow Truck debut hyper-fuel-efficient Class 8 concept truck” https://www.sae.org/news/2018/03/shell-airflow-truck-debut-hyper-fuel-efficient-class-8-concept-truck.)

“If we brought many of the existing technologies together, how good could we be?” Bob Mainwaring, Technology & Innovation Manager, Shell Lubricants, said. “We thought that would be a really interesting thought experiment, if not real experiment,” he told Truck & Off-Highway Engineering at the Starship Initiative’s finale event in Jacksonville.

Chris Guerrero, Global Brand Manager, Heavy Duty Lubricants, explained that Shell also considered the concept as an opportunity to get a conversation started across the trucking industry. Was the original thought to produce a truck like this one? “No, I think the idea was more of the art of what is possible,” Guerrero said.

As it turns out, Airflow Truck Co. owner Bob Sliwa had been thinking the same way.

Results of the test run

At the Starship’s finale event, Carlos Maurer, President, Shell Lubricants Americas, told media gathered to hear the results of the test drive, “This is about the iterative process. We’ll continue to learn; we’ll continue to improve.” Maurer explained that he considered the results of the test run as just the baseline. “I think we will get much better as time goes by.”

The North American Council for Freight Efficiency (NACFE) recorded and validated the results of Starship’s run. Starship achieved the 178.4 ton-mpg for FTE, which is a more relevant statistic for judging the energy intensity associated with moving cargo from point A to point B since it combines the weight of cargo being moved with the amount of fuel consumed.

The Starship truck had a total average fuel economy of 8.94 mpg (17.27 km/gal), compared to the average U.S. fuel economy for transport trucks of 6.4 mpg (12.3 km/gal). The best fuel economy attained during the drive was 10.2 mpg (19.7 km/gal).

The final total truck and cargo weight was close to 73,000 lb (33,112 kg)—28% heavier than the average total gross vehicle weight of 57,000 lb (25,855 kg) for a U.S. on-highway Class 8 truck. The 39,900 lb (18,098 kg) payload had 77% more mass than the U.S. average payload of 22,500 lb (10,205 kg), and was comprised of clean reef material destined for a new offshore reef installation in Florida.

And, in terms of calculating estimated CO2, if all trucks in the U.S. (about 2 million) reached the overall fuel economy and FTE performance of Starship, they would emit an estimated 229 million fewer tons of CO2 into the atmosphere per year. A reduction of 229 million tons would correspond to a 60% reduction in CO2 emissions from the U.S. truck fleet.

Onboard the Starship

To acheive these results with the Starship, Shell and Airflow focused on aerodynamics, rolling resistance, engine efficiency, driveline efficiency and driving style.

The cross-country journey provided Shell with an opportunity to test Shell Rotella T6 Ultra 5W-30 Full Synthetic engine oil in a vehicle prior to its introduction to market. This low-viscosity API FA-4 engine oil is formulated to provide better fuel economy, improved high- and low-temperature performance compared to CJ-4 performance engine oils, and meets the requirements for many low emissions engines.

The combination of Shell lubricants technology, carefully thought-through aerodynamics, including customized carbon-fiber cab (which Guerrero told TOHE they initially attempted to produce through 3D printing, but ultimately were unable to because the 3D printing technology isn't there yet for the size needed—another learning experience that the team gained through this initiative), as well as full side skirts along the length of the trailer, a 400-hp (298-kW) Cummins X-15 Efficiency engine, Bridgestone’s low rolling resistance tires, and a smart driving strategy all contributed to the FTE result.

The active grille shutter on the truck, supplied by Röchling Automotive, can help improve the mpg or FTE. "Although the shape itself of Starship was extremely aerodynamic and had a lower coefficient of drag compared to many vehicles on the road today, this was where we saw an opportunity to still improve and worked with Bob [Sliwa] to come up with a solution," said Ryan Forman, Product Manager, Aerodynamics and Engine Encapsulation Systems. 

He explained that the shutter system is positioned behind the Starship's grille. When air is needed to cool the cooling pack, the vane can be opened, but it can be closed when air is not needed to redirect the air around the vehicle. When there is a cold-temperature climate, the shutters and vanes can be closed to help improve engine warm-up time. When looking at an internal-combustion engine on a traditional vehicle, incorporating this product can help reduce engine warm-up time by 50%.

A late addition to Starship was recently DOT-approved full-video-only aerodynamic mirrors, adding to the streamlined design. The mirrors provide a nearly 180-degree view on each side of the truck. Sliwa explained the switch, made just prior to hitting the road, took a couple of days to get acclimated to and said they performed better at night than traditional mirrors.

As far as the future of the project is concerned, Shell and Sliwa both talked about improvements and additional efficiencies that are possible in the next phase of Starship. "I'm excited to tweak it," Sliwa said. Continue reading »
X