August 26, 2023

Viewpoint: 10 mpg in a Class 8 on the open road? Yes, it’s doable


By Joel Morrow

The views expressed here are solely those of the author and do not necessarily represent the views of FreightWaves or its affiliates.

According to American Transportation Research Institute’s latest Operational Cost Update, semi-truck drivers in the U.S. get average fuel economy of around 6.68 miles per gallon. 

After putting 50,000 miles on my new truck — a  Volvo D13 with I-Torque — hauling general van freight over the road on coast-to-coast routes, I’m averaging over 10.1 mpg. That means I’m saving almost $5,000 on fuel costs every 90 days compared to typical drivers.  

How is this possible?  It’s a combination of technology and technique. The great news is most drivers can use my tips to improve fuel economy and save money.

I know bottom-line profitability is typically what matters most to truckers. But it’s also worth noting that driving 100,000 miles at my fuel economy prevents 55 metric tons of carbon dioxide from entering the atmosphere. Improved fuel economy means better air quality. And that’s something to feel good about.

Let’s break down the factors contributing to my hyper fuel efficiency.


Aerodynamic resistance is a huge factor in fuel economy, and aero resistance increases exponentially as you go faster. To reduce aero resistance, make sure your roof fairing is aligned to the height of your trailer, install back-of-cab extenders, and lower side chassis fairings between the wheels and over the fuel tanks. A trailer side fairing is fairly standard to comply with California Air Resources Board regulations.

We are about to do a trailer aerodynamics upgrade that includes a custom-designed, bigger side fairing, as well as adding a trailer gap fairing and a trailer tail device. Aerodynamics improve up to 4% with a trailer tail, which can extend up to 5 feet behind the truck, angled to a point to smooth out the wake behind your trailer. Did you know colder air is denser and impacts air resistance? That’s one reason fuel economy goes down in the winter months. That’s also why crosswinds are more dangerous in colder weather.

Following distance

Forward-looking radar drives a lot of professional truckers crazy. Typically, drivers are great at judging distance but not necessarily time within that distance. Radar does a good job of figuring that out. Traveling 75 mph requires a gap to other traffic that needs to be twice as big. Longer following distance also means fewer reactions to erratic drivers. That allows more room for constant throttle. I try to run a couple miles per hour slower than the posted limit so that traffic in front of me is constantly pulling away. This makes you a safer driver. And I’ve found that usually results in lower maintenance costs.

6×2 configuration

Anytime you have fewer gear sets engaged, mechanical drag and friction is minimized. And running axle-up makes a big difference in fuel economy. But advanced technology is the driving force rather than having two fewer tires on the pavement.

Weight is a determining factor in when you can run on one drive axle. On my truck, adaptive torque management prevents wheel slippage. It is included as part of the factory 6×2 standard configuration. Additionally, the adaptive loading system monitors trailer weight to automatically raise the pusher drive axle up to about 55,000 pounds gross combination vehicle weight, depending on weight distribution and how the load sits on the trailer floor. 

Downsped RPMs

Most people don’t believe me when I tell them I’m rolling at highway speeds just above idle RPM. The truck is spec’d to do 65 mph at about 940 RPM, so the engine pulls less fuel because there are fewer piston strokes per minute. Fewer strokes mean less engine friction, which improves fuel economy further. Not all engines are optimized for downsped RPMs, but my engine is specifically designed for making peak horsepower at 1260 RPMs and peak torque at 900 RPM. It only takes drivers about 50 miles on the road to understand the physics of this setup and realize they don’t need to run at 1,700 RPM. Downsped RPMs also reduce vibration and engine wear. Also, the pistons are moving more slowly, so the combustion chamber burns fuel more efficiently and slightly hotter, which also means after-treatment systems run cleaner and require less maintenance.

Automated manual transmission with look-ahead

I know a lot of old-school drivers prefer a manual gearbox, but I spec’d my truck with a 14-speed automated manual transmission option. The reason I picked this setup is that the truck has integrated map-based software from the factory, which downshifts in anticipation of an upcoming grade, rather than relying on my interpretation of when that shift should occur. As such, this optimizes both power for climbs and fuel economy. In my spec, this is paired with a 2.16 rear axle ratio through an overdrive transmission for a final drive ratio of 1.69 — the fastest final drive in the industry. That ratio is only possible because the engine has been optimized for peak horsepower at such a low RPM.

New technology

I’ve driven more than 5 million miles as a professional trucker, and I try to listen and learn what I can about new technologies. That’s how I spec’d my truck, and I embrace technology now, including my fuel-efficiency monitoring. I use a helpful app from called FuelGauges and have dashcams to document road conditions. If you don’t track your fuel economy, you can’t be honest with yourself about your driving habits. And your fuel economy will never improve. 

Time management

Beyond leveraging technology, I’ve found that good time management reduces stress and lowers your blood pressure because you’re not as angry at traffic conditions. Don’t leave late. If you stop at the house, if things don’t always go right, or if you don’t leave time for life to occur, then you are standing on the throttle constantly, which is bad for safety, bad for truck health, terrible for fuel economy, and takes a physical and mental toll. I get a lot of flak for “driving slow,” because some look only at my average speed. But good time management takes patience and planning, and it requires a more comprehensive approach to your business than thumping tires, changing duty status and holding the steering wheel.

Joel Morrow says time management and attitude contribute as much as technology to better fuel efficiency. (Photo: Joel Morrow)


Finally, attitude has a huge impact on daily performance. Your morning attitude is so important to being a safe and efficient driver. If you wake up upset, it’ll be extremely difficult to be efficient, and that’s something that I had to work at. It can be hard to keep your mind happy and focused, and I had to do some soul searching a few times to sort out my outlook and attitude to understand myself and consider whether trucking is the right choice for me. Attitude also has a big impact on health. As many drivers get closer to home, they get emotional and might be putting their foot down to make it to an important family event on time. We all need to set realistic expectations.

Things are changing fast, and whenever there’s a slow patch in the freight economy, it will be those drivers who have optimized costs and in particular fuel efficiency who will fare better and stay profitable. Perhaps none of these attributes by itself will change your business. In aggregate, it has proved to be a competitive advantage. Follow these tips and you will be more profitable, enjoy driving more and realize better health.

Want to know more? Hop in the virtual passenger seat of my truck, Purple Haze, and follow my drives to learn more.

Joel Morrow is co-founder of Alpha Drivers Transportation, an independent OTR carrier. You can follow his fuel-efficiency blogging from his daily driving, on and on Facebook.


The second annual F3: Future of Freight Festival will be held in Chattanooga, “The Scenic City,” this November. F3 combines innovation and entertainment — featuring live demos, industry experts discussing freight market trends for 2024, afternoon networking events, and Grammy Award-winning musicians performing in the evenings amidst the cool Appalachian fall weather.

Source link
In this article:
Share on social media: