Diesel prices are rising, climate change is real, and freight volumes are growing. America needs to keep running and freight needs to move, so how can the trucking industry tackle all three?
There is one thing that can have a positive effect on all these areas – improving fuel mileage. The trucking industry is always working on it, but as diesel prices are rising, the industry’s quest for raising a typical truck’s miles-per-gallon (MPG) efficiency has become more pressing. For trucking, the golden number has become 10 MPG, and it’ll take a combination of manufacturing, engineering, company policy, and the drivers themselves to get there.
In 2018, the transportation sector contributed 28% of all U.S. carbon emissions. Transportation encompasses all areas of U.S. travel – including regular pedestrian automobiles, boats, airplanes, and rail – but approximately 23% of those emissions come from freight trucks like mine. That might not sound significant, but that 23% equates to roughly 439.7 million metric tons of C02 emissions.
Manufacturers for traditional, civilian automobiles – the largest carbon emitters – have begun to take climate change more seriously. Even as Trump relaxed the fuel economy standards in 2020, five of the world’s largest automobile makers signed a deal with the state of California that would make them adhere to its stricter carbon emission guidelines. As such, many of these companies are diverting their resources to designing hybrid or fully electric cars.
In many respects, similar changes in the trucking industry are much harder to implement. While civilian cars carry passengers and some luggage in the truck, freight trucks haul many tons of goods across long distances. They need power and endurance. A such, reaching 10 miles-per-gallon is not as simple as renovating an archaic fleet of freight trucks with a new engine. Designing a 10 MPG truck is closer to crafting a NASA rocket than a traditional car.
The most apparent change to freight trucks is mainly aerodynamic. Modern freights no longer have a flat-fronted chassis but are pointed – like large carbon bullets. The goal is to get the air to move either over or around the truck. Letting it under the truck is bad, so front bumpers are being made of more flexible material are rounded, and are closer to the ground. The hoods have become angled downward, the top of the truck is as high as the trailer, and the windshields and even the mirrors have become more rounded.
For an 18-wheeler that spans between 70-80 feet, even a few inches of spacing could make a difference. The gap between the truck and trailer has gotten smaller, so the trailer doesn’t create a second hit of air. But conversely, if the trailer is too close to the truck it will hit the cab during tight maneuvers. Today, the goal is to keep the trailer no more than 18 inches from the cab.
And then there are the tires. The traditional 18-wheeler may have as few as 10 tires. Over time, wide-based single tires have grown to replace the more traditional set of two tries to reduce the spinning weight of the combination vehicle by over 500 pounds.
In the trucking industry’s quest for 10 MPG, they have made other changes on the outside. There are more trailer skirts to prevent air drag, the trailer floors are supported by newer beams, and there are heavier axels. When I asked some aero engineers how they design these new trucks, they equated their shape to that of a kayak. There is a reason that kayaks don’t have square backs: so, the water flows seamlessly in its wake. Then they said if you really want to know how aerodynamics work, look at hydrodynamics.
There are also noticeable changes under the hood.
I have always taken pride in how smoothly I could shift gears, but drivers are no longer shifting gear manually. The drive train – engine, transmission, axle ratios – have evolved. Engines are producing the necessary torque at fewer RPMs than they used to. Basically, the slower the engine spins the less fuel that it uses. Automated manual transmission dominates the market.
State-of-the-art GPS systems with cruise control make sure that no fuel is wasted. The truck, for example, is constantly planning 2 kilometers ahead. It will slow just before it peaks a hill and let gravity pull it down. This system is called ‘passive cruise control,’ so when you set your cruise at 62 in the truck will set a range of say 58-67 miles per hour. This range allows the truck to save fuel with the changing topography.
Helping to make the trucking industry more fuel-efficient is not a simple fix. Our quest for 10 MPG is not just changing one variable, but a series of alterations that add up. Still, with all of that being said, drivers still matter. All these changes will be obsolete in the hands of an incapable trucker, so the industry must also help our new recruits to teach them how to drive well, not just avoid getting into an accident. The future of our industry hangs in the balance.