How to Get Better Fuel Economy from Your Semi-Truck

Fuel is one of the largest operating expenses for any trucking company or independent operator. Fortunately, there are several practical and mechanical strategies that can significantly improve fuel economy in your semi-truck.

Understanding the Importance of Fuel Economy

Fuel economy isn’t just about saving a few bucks at the pump—it’s about long-term sustainability and performance. Poor fuel efficiency leads to:

• More frequent refuelling
• Higher emissions
• Added wear on your engine and components

Optimizing your fuel efficiency means your semi-truck runs cleaner, smoother, and longer.

Perform Routine Preventive Maintenance

Nothing kills fuel economy faster than a poorly maintained truck. Dirty air filters, misaligned wheels, and low tire pressure can dramatically increase rolling resistance and reduce engine efficiency.

Key Maintenance Areas:

• Air Filter Replacement: A clogged air filter forces the engine to work harder, consuming more diesel.
• Oil and Fluid Checks: Using the correct engine oil viscosity improves lubrication, which reduces internal friction.
• Tire Pressure Monitoring: Under-inflated tires create more drag; check pressures daily, especially in Oklahoma’s fluctuating temperatures.
• Fuel System Cleaning: A clean fuel injector ensures optimal spray patterns for efficient combustion.

According to industry data, a well-maintained vehicle can improve fuel economy by as much as 10%.

Driving Habits

How a truck is driven significantly affects how much fuel it burns. Aggressive acceleration, inconsistent speed, and unnecessary idling are notorious fuel wasters.

Adopt These Driving Techniques:

• Use Cruise Control: Especially useful on Oklahoma’s long highways. Maintains a constant speed and prevents unnecessary throttle input.
• Avoid Hard Braking: Instead, coast whenever possible. Every time you hit the brakes, you're wasting momentum that cost fuel to create.
• Shift Efficiently: For manual transmissions, shift at the engine's optimal RPM. Over-revving increases fuel usage.
• Minimize Idle Time: Excessive idling, especially in extreme weather, burns fuel with zero mileage return.

ECM Tuning for Fuel Efficiency

Your Engine Control Module (ECM) dictates how your engine manages fuel injection, air intake, and emissions. A fuel economy tune can recalibrate these settings for optimized fuel efficiency.

While performance tuning may provide more power, it often sacrifices MPG. On the other hand, fuel economy tuning adjusts parameters like throttle response and shift points to reduce fuel consumption without harming reliability. However, ECM tuning should only be carried out by experienced professionals to avoid damaging sensitive components or violating emissions standards.

Manage Aerodynamics

Air resistance is a major drag—literally. At highway speeds, nearly half of an engine’s power is used to overcome aerodynamic drag.

Aerodynamic Enhancements:

• Roof Fairings & Side Skirts: These redirect airflow more efficiently around the cab and trailer.
• Trailer Tails: Reduce turbulence at the rear of the trailer, improving fuel economy by up to 5%.
• Close the Gap: Use cab extenders or adjust the trailer’s position to reduce the gap between the cab and trailer.

Even minor changes in aerodynamics can deliver major savings over long distances.

Use the Right Tires and Alignments

Rolling resistance is a silent fuel thief. Choosing low rolling resistance tires and ensuring regular alignment checks is one of the easiest ways to cut fuel costs.

• Tire Selection: Consider switching to SmartWay-certified tires that are specifically engineered for better efficiency.
• Alignment Checks: Misaligned axles increase drag and wear out tires faster, reducing fuel mileage.

A properly aligned semi-truck uses less energy to stay on course, translating directly to fuel savings.

Monitor Load and Weight Distribution

Excessive and uneven weight distribution not only wears out tires and suspension components but also taxes your engine.

• Don’t Overload: Heavier trucks burn more fuel. Stay within weight regulations and monitor load efficiency.
• Balanced Distribution: Keep cargo centered and evenly spread to prevent drag and ensure better traction.

Load optimization not only saves fuel but also improves driving safety and vehicle longevity.

Invest in Advanced Telematics

Modern fleet telematics systems track idle time, speed, engine diagnostics, and driver behavior in real time. These systems help identify areas for improvement across your fleet.

• Fuel Reporting: Detects trucks with poor fuel performance.
• Driver Scorecards: Tracks idling, speeding, and gear shifting habits.
• Maintenance Alerts: Prevents fuel-wasting breakdowns.

By analyzing this data, fleet managers can set measurable goals and deliver training to improve fuel-efficient driving habits.

Keep Up with Emissions and Aftertreatment Systems

Modern diesel trucks are equipped with aftertreatment systems like the Diesel Particulate Filter (DPF) and Selective Catalytic Reduction (SCR). If these components clog or malfunction, they can cause the engine to consume more fuel to maintain performance.

• Perform Regular DPF Regeneration: Prevent clogging by ensuring proper regeneration cycles.
• Monitor DEF Levels: Low Diesel Exhaust Fluid can trigger reduced engine performance, leading to higher fuel usage.
• Check EGR Valves: A failing Exhaust Gas Recirculation valve increases combustion temperature, decreasing efficiency.

Keeping these systems in optimal shape ensures emissions compliance and maximum fuel economy.

Consider Auxiliary Power Units (APUs)

If your semi-truck spends a lot of time idling to power HVAC or electronics during rest periods, an auxiliary power unit can be a game-changer.

An APU provides electricity and climate control without idling the main engine, significantly reducing diesel consumption during downtime.

Make Every Mile Count

Improving fuel economy in your semi-truck is not a one-time fix—it’s an ongoing strategy that includes smart driving, routine maintenance, aerodynamic enhancements, and leveraging modern technology.

If you require preventive maintenance services in Oklahoma City, reach out to our team at OKC Fleet Services today.