How maintenance saves fuel
- Optimizing tires and alignment: Chronic underinflation, poor tread depth, and minor wheel misalignment silently degrade fuel efficiency. Implementing strict preventive maintenance checks and utilizing SmartWay-verified tires ensures your fleet isn't burning unnecessary fuel.
- Prioritizing airflow: Clogged or dirty air filters force the engine to work harder, directly wasting fuel. Maintenance teams should rely on restriction gauges rather than visual inspections alone to replace filters at the optimal interval.
- Fuel quality and lubricant precision: Using cheap or stagnant fuel from low-volume stations risks engine efficiency due to algae and contamination. Pairing high-volume fuel with OEM-approved, efficiency-grade oil blends ensures internal systems run at peak performance.
- Leveraging tech and OEM updates: Skipping software updates limits fuel efficiency. Prioritizing routine OEM updates keeps electronic control modules optimized, while monitoring telematics data—like idle shutdown and road speed limiters—helps correct fuel-wasting driving habits.
In the past few months, the cost of diesel has gone through the roof. After surviving the chaotic uncertainty of tariffs in 2025, procurement teams and maintenance directors have spent most of the first half of 2026 contending with fuel costs nearly 100% higher than budgeted.
Even once conflict is fully resolved and the Strait of Hormuz is operating normally, fuel prices likely won’t reach pre-war levels until early 2027—maybe. And this doesn’t account for anything else that might come up in the latter part of the year.
As frustrating as high fuel costs are, they can be managed. By taking care of a few key areas on your trucks, being mindful of your oil and fuel sources, and performing regular OEM software updates, fleets can avoid feeling sunk by the price at the pump.
Why fuel management is important
Everyone is painfully aware that fuel is expensive in June 2026. But let’s face it: Most of the time, what we pay at the pump only seems enviable in hindsight. Periods where diesel is exceptionally inexpensive happen far less than the inverse, meaning most of the time we expect to pay more for fuel than less.
No one ever says “diesel is cheap right now” to justify buying more trucks or opening a new location. Cheap fuel is fleeting.
As one of the largest operating costs for fleets, even small increases at the pump can put your profitability on the line. Fortunately, fuel is also one expense that maintenance managers and others can control much more directly through their decisions and guidance.
To help you know where your efforts are optimally served, I suggest focusing on mechanical aspects like tires, air filters and wheel alignment; oil type and fuel source; and finally, OEM software updates and monitoring.
Take care of your trucks
Ensure your trucks aren’t burning unnecessary fuel by looking after the tires, air filters and wheel alignment across your fleet.
Tires are one of the biggest drivers of fuel economy. Unfortunately, they’re often some of the most neglected components on a truck. Are they chronically underinflated? Improper pressure degrades fuel economy but is easily checked and remedied.
What kind of condition are they in? Low tread depth, warping, bubbles and other signs of damage and wear indicate a tire needs to be replaced—otherwise, efficiency will suffer.
If you’re ready for replacements, consider a fuel-efficient tread pattern, often indicated by the SmartWay verification. Most tire manufacturers offer products that don’t compromise fuel economy for durability or longevity.
While you’re inspecting the tires, don’t forget about the wheels and alignment. Misalignment accelerates tire degradation and impairs fuel economy but might go unnoticed if you don’t conduct routine preventive maintenance.
Meanwhile, dirty air filters restrict airflow and force the entire system to work harder to maintain circulation. Replace these at the recommended interval, regularly inspect their condition and decide if new ones might be needed sooner. And don’t just rely on a visual inspection—filters that appear dirty may well be working efficiently. A dash- or housing-mounted air filter restriction gauge is your best bet for monitoring filter life.
Lubricants: quality, source, type
Along with tires and other parts, lubricants play a major role in your fleet’s efficiency.
First off, the quality of diesel you use to fuel your trucks has a significant impact on how efficiently they run. When the price spikes dramatically, it can be tempting to find a relatively cheaper alternative to mitigate the increased expense. But while this might save you a few dollars at the pump, you could end up paying down the road.
Alternative fuels like biodiesel and E85 also present an avenue for savings—but only if you have a compliant engine. Contact your OEM before adding biodiesel or an equivalent to the tank. You can do serious damage if the engine isn’t built for these mixes, and many OEMs will recommend shortened PM intervals if you go that route.
Something else to watch is where drivers purchase fuel on the road. Do they mostly stick to major, recognizable brands at high-volume stops? Or are they fueling at lesser-known, low-volume locations?
With the latter, you run a greater risk of fueling with lower-quality diesel. Since fewer trucks are filling up, the fuel sits for longer periods in underground storage tanks—a breeding ground for algae during the hot summer months. A higher-volume station refills its storage tanks more often, so the diesel isn’t stagnant. Cleaner fuel translates to better efficiency and performance.
With PC-12 coming soon, understanding your fleet’s engine oil needs has never been more important. Again, just like using alternative fuels, check with your OEM before switching a truck to a different oil type or weight, since using the wrong kind can irreparably harm the engine, even if it’s meant to improve efficiency.
However, when done properly, changing over to a more efficient oil blend has a positive impact on fleet efficiency. It comes down to using the right type of oil in the right truck.
Use tech to your advantage
If you’ve taken care of your trucks’ condition and lubricants, one final area you can look to for fuel savings is on the tech side. Tracking parameters and updating systems when prompted ensure you’re staying up to date and maintaining visibility over key indicators of efficiency.
As irksome as constant update reminders can feel, you might want to rethink hitting “Remind me later.” The majority of updates from OEMs don’t take very long to run and have a measurable impact on fuel economy. Maintenance managers should prioritize running these to keep ACMs and other software as up to date as possible.
Most fleets have telematics devices installed, which means shops can access more information about the trucks they’re servicing than ever before. I recommend maintenance managers review two parameters: idle shutdown and road speed limiter.
Though idle shutdown will turn off the engine if the truck idles too long, there could be a pattern behind the data. Is it one driver in particular? A specific route or customer? Understanding and correcting the root causes helps you know where your operations and fleet efficiency could improve.
Speed plays a major role in fuel economy. According to Cummins, at 55 mph and above, each 1 mph increase in speed decreases efficiency by 0.1 mpg [1]. That means you’re already losing a full mile per gallon at 65 mph. As insignificant as that sounds on paper, when extrapolated across hundreds of vehicles traveling thousands of miles in total every single day, the result is millions of dollars in added expense.
Being smart is always smart
High fuel prices are something we all feel. Mitigate the impact on your bottom line by keeping vehicles in good working order, paying close attention to the tires, air filters and alignment.
Make informed purchasing decisions about fuel and lubricants, and keep an eye on key parameters like idling and road speed. When fuel prices eventually do come down, these strategies will keep paying dividends.
