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The AirFlow Starship Aims To Break All Records For Class 8 Truck Fuel Efficiency

Major efforts have been undertaken in both reducing drag and imroving efficiency of the StarShip

The area under the cab of the Starship is completely flat in order to improve aerodynamic efficiency

With new cars being designed with improved aerodynamics to assist both performance and reduce fossil fuel consumption, the trucking industry is looking at the same issues. No doubt you’ve seen Class 8 tractor-trailer rigs with devices fitted like roof fairings, aerodynamic side mirrors, cab extenders to help fill the gap between cab and trailer, and side fairings hanging from the bottom of the trailer itself. In fact, there are probably more aero add-ons available for a big rig than a Honda Civic.

But what’s the actual effect if one were to take an integrated approach to optimize all areas of the tractor-trailer that the wind passes over? That’s what Bob Sliwa has been pondering since he founded AirFlow Truck Company in 1983. After a misspent youth drag racing a 1965 GTO and then a 1966 L88 Chevelle SS he decided to start a trucking company, first as an owner-operator.

Fast forward to 2009 when AirFlow developed its first hyper-efficient Class 8 rig. Equipped with a K&N air filter and nicknamed the BulletTruck, its nose looked like a cross between a Shinkansen and an NHRA Pro Stocker.

The solar panels are capable of generating 5000 watts of electricity that can help run the truck

The gap between cab and trailer is electonically-controlled while solar panels contribute power

AirFlow has now partnered with Shell and its Rotella brand of diesel lubricants to develop the most fuel-efficient Class 8 tractor-trailer combination ever to hit the road. This next-generation concept truck, named Starship, features an integrated aerodynamic design applied across the rig. Some of the features are active, rather than passive as in existing trucks, meaning they will respond to the circumstances in which the truck is being operated to maximize efficiency.

For example, the drag-inducing space between cab and trailer is closed by an electronically-controlled gap sealer. The system monitors the position of the truck in relation to the trailer retracting the sealer so that tight turning maneuvers don’t damage the gap sealer but then moves it back into place at highway speeds.

The underside of both the truck and trailer is completely flat, which eliminates a great deal of turbulence-induced parasitic drag that the engine must overcome, especially at highway speeds. This both increases fuel consumption but also limits the revenue-generating load the truck can carry.

Air flow management is a critical component of the StarShip's design

Even how the air exits from under the hood has been treated for aerodynamic efficiency

The trailer itself benefits from the extensive use of carbon-fiber material, which is not only exceptionally strong and lightweight but can be molded into aerodynamically-efficient shapes. The same material is used for the cab as well.

On the roof of the trailer is a 5000 watt solar array, while there’s a regenerative braking system on the trailer’s rear axle that collects otherwise lost energy on downhill runs. Power can be stored in a battery system like a Tesla, then used to drive the electrical systems of the truck (eliminating the drag of an alternator, thus achieving yet another improvement in engine efficiency).

The engine is an X15 high-efficiency diesel from Cummins, offering the highest fuel economy in the industry. Because of the aerodynamic efficiency of the Starship, it doesn’t need to push its engine as hard as conventional trucks. So instead of running at the advertised governed speed of 1800/2000 rpm, the StarShip will redline at 1100 rpm, contributing to significant fuel savings. The engine is fitted with a unique Eaton transmission modified specifically for the Starship.

Those fuel savings actually relate to the weight capacity of the truck as well. Instead of the standard 250-gallon fuel capacity, the Starship will be fitted with a 100-gallon fuel tank. At seven pounds per gallon for diesel fuel, that’s a weight savings of over a half a ton that can instead be used to carry revenue-generating cargo.

The aerodynamics panels help the air reattach after passing over the truck, reducing drag

Even the trailer end has received an aerodynamic treatment to further reduce parasitic drag

The 15L DOHC 16-valve X15 engine features a variable-geometry turbocharger fed by an advanced prototype K&N air filter based on the 38-2027S, as builders wanted the filter to fit in a stock housing. Lessons learned from K&N’s participation in this project will be applied to improve future filter designs.

Improvements in aerodynamics on the truck have netted a 50% reduction in drag versus current trailer-trailer combinations. But there are other areas, particularly those affected by friction, that are addressed on the Starship as well, including low viscosity synthetic lubricants, low rolling resistance tires whose inflation pressures are constantly monitored and maximized for economic operation and long wear.

If you’re going to be attending the Mid-America Trucking Show in Louisville, Kentucky, from March 22 through March 24, be certain to stop by the Shell booth and take a first-hand look at the future of trucking as exemplified by the AirFlow Starship.


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