Fuel Costs: Managing Your Biggest Controllable Expense

Diesel is your single largest expense. Unlike many costs, fuel cost per mile is something you can actively manage. But first, understand the scale of the problem.

The size of the fuel bill

An owner-operator or small carrier typically burns 18,000 to 22,000 gallons per year, depending on equipment and utilization. At retail diesel prices, that’s a massive expense.

Current benchmark (volatile — see below): EIA reported US on-highway diesel at $5.403/gallon as of April 20, 2026. At 20,000 gallons per year, that’s over $108,000 annually in fuel alone.

This number ages fast. Diesel prices move weekly based on crude oil, refinery capacity, and seasonal demand. The figure above was current on the date it was measured, but fuel prices shift 10–20 cents per gallon in weeks. Check the current EIA weekly diesel price before making any major decision based on current fuel cost. Your year-to-year fuel budget should account for price volatility, not assume a single fixed price.

Strategy 1: Fuel cards and volume discounts

What fuel cards do: A fuel card from a branded network (Murphy Express, Love’s, Shell, or Pilot/Flying J) typically bundles discounts across that network plus sometimes a rebate based on volume.

Real savings data: Network members in NASTC and TCS Quality Plus reported averaging around $0.50 per gallon in savings over the past two years. This is the combination of pump-price discounts and periodic rebates.

Fixed-price vs. percentage rebates: When prices are volatile (which they are), fixed-price discounts tend to outperform percentage rebates. If a fuel card gives you “a $0.50 discount” and prices drop to $4.00/gallon, you still get $0.50 off. If it gives you “3% rebate” and prices drop, your rebate shrinks with the price. In volatile markets, fixed savings beat percentage savings.

Multi-card strategy: Some carriers use multiple cards strategically — one for primary fuel, one for backup at specific locations, one for loyalty points. But that adds complexity. Start with one card from a major network that covers your regular routes.

Strategy 2: Speed and idling discipline

Speed kills fuel economy. Aerodynamic drag rises sharply above 65 mph, so every mph you add above that costs measurable MPG — the exact rate depends on your tractor/trailer aerodynamics, weight, and engine, so treat any single number as illustrative, not a constant you can apply to your own truck. As an illustrative example only, for a driver averaging 6 MPG at 65 mph:

At 65 mph: 6 MPG over 20,000 annual miles = 3,333 gallons
At 70 mph: ~5.5 MPG over 20,000 annual miles = 3,636 gallons
The difference in this example: 300+ extra gallons per year, or roughly $1,500 at current prices.

Because the exact figures depend on your equipment, treat the numbers above as an illustration rather than a fixed rule. Most ELD and telematics systems report your own MPG-versus-speed data; reviewing it for your specific tractor and trailer will give you a far more accurate basis for setting a governed speed than any general benchmark.

Idling costs money every minute. An 8-hour idle burns about 1 gallon per hour (varies by engine, but this is typical). That’s $10–$15 per workday spent on idling alone.

Practical action: Set governed speed limits in the truck at 63–65 mph if your fleet allows it. Use APUs (auxiliary power units) for sleeper cabs instead of idling to maintain temperature. Educate drivers that fuel economy is part of their job — some carriers tie a portion of driver pay to fuel efficiency.

Strategy 3: Route and fuel-stop planning

Know the price map before you leave the yard. Fuel prices vary 10–30 cents per gallon across regions and even between adjacent truck stops (highway vs. off-highway, brand vs. independent, etc.). Plan your fuel stops around price, not convenience.

Tools: GasBuddy, Pilot Flying J’s app, and some telematics systems show real-time prices at truck stops on your route. Spend 5 minutes planning before leaving — it pays.

Monthly benchmarking: Track your fuel cost per gallon and per mile. If your MPG drops or your per-gallon cost climbs unexpectedly, something’s wrong (bad maintenance, driver behavior, or load weight creep). Catch it early.

Strategy 4: Maintenance

Poor maintenance destroys fuel economy.

Tire pressure: Underinflated tires increase rolling resistance. Keep tires at spec.
Engine condition: A truck burning oil or running rich uses more fuel. Regular tune-ups matter.
Aerodynamics: Trailer skirts and tractor fairings reduce drag. A clean, aerodynamic rig uses less fuel.
Weight: Useless weight (extra equipment, unused cargo racks) burns fuel. Clean out what you don’t need.

The numbers in context

At 20,000 gallons per year and $5.40/gallon, fuel is $108,000. If you improve MPG by 0.5 miles per gallon (realistic with speed discipline and fuel-card savings combined), you cut 1,852 gallons from your annual burn. That’s $10,000 in savings.

Is it worth tracking fuel stops and managing driver speed? Yes.

→ See the fuel and IFTA basics for tax reporting details.

→ Find fuel cards and networks in the providers directory.

Key takeaway

Fuel costs move weekly. Don’t hardcode a fuel budget based on today’s price — account for volatility. But the levers you can pull (fuel cards, speed discipline, stop planning, maintenance) are under your control and add up to real savings. Start with fuel cards and speed governs. Add telematics and per-driver incentives as you scale. The margin is in the details.