Fuel is one of the highest operating costs in trucking, and even small MPG improvements can add up to thousands of dollars saved each year. Industry research shows that improving fuel efficiency by just one mile per gallon can save several thousand dollars annually for a long-haul truck. This guide breaks down proven ways drivers can improve semi truck fuel economy through driving habits, maintenance, and smart equipment choices.
Key takeaways:
- Cruising speed matters most - fuel burn climbs fast above 65 mph, so keeping speed steady in the 55-65 range usually helps MPG and can significantly reduce fuel consumption compared to driving 75 mph.
- Tire pressure saves money - tires underinflated by 10 psi can increase fuel use by about 0.5-1.0%, making regular pressure checks one of the simplest ways to protect efficiency.
- Smart route planning cuts costs - using tools like OTR Fuel Finder helps drivers locate discounted fuel stations along their routes, saving an average of $0.50 per gallon.
- Regular maintenance protects efficiency - clean air filters, proper wheel alignment, and well-maintained engines can improve fuel economy by 3-10% over neglected equipment.
What is the fuel economy of a semi truck?
Class 8 semi trucks typically achieve fuel economy between 5 and 8 miles per gallon, with most long-haul operations averaging in the mid-6 MPG range. Newer, aerodynamic trucks achieve higher numbers while older or heavily loaded trucks fall below that range.
Fuel efficiency varies significantly based on truck age, equipment specifications, and operating conditions. Modern trucks equipped with aerodynamic enhancements and efficient powertrains can reach 8-10 MPG or higher under optimal conditions, while older equipment or heavily loaded vehicles may struggle to reach 6 MPG on challenging routes.
Typical MPG ranges for semi trucks
- Average MPG: 6-7 MPG for standard long-haul operations
- Efficient modern trucks: 8-10+ MPG with aerodynamic equipment and optimal driving
- Older or heavy trucks: Under 6 MPG with challenging loads or poor maintenance
According to the Environmental Protection Agency, fuel economy continues to improve industry-wide as carriers adopt newer equipment and implement driver training programs. Some carriers use steadier cashflow to stay consistent with maintenance schedules and planned upgrades that support better fuel efficiency over time.
What affects semi truck fuel economy?
Semi truck fuel economy is influenced by mechanical condition, driving behavior, speed, load weight, aerodynamics, and environmental conditions. Each of these factors can have a measurable impact on how many miles you get from each gallon of diesel, and many are within the driver's direct control.
Fuel is often one of the highest operating costs for carriers, and it can make up a large share of the cost per mile depending on diesel prices. Small improvements across multiple factors can compound into significant annual savings, making fuel economy optimization one of the most impactful areas for carriers to focus on when managing their operations.
Key factors that impact fuel economy
- Cargo weight - heavier loads require more fuel to accelerate and maintain speed, especially on grades
- Speed - wind resistance increases exponentially above 55 mph, dramatically reducing efficiency
- Road and weather conditions - headwinds, rain, snow, and rough pavement all increase fuel consumption
- Driver habits - aggressive acceleration, hard braking, and excessive idling waste fuel
- Maintenance and aerodynamics - worn equipment and poor aerodynamics create unnecessary drag and resistance
Carriers using freight factoring services can maintain steady cashflow to address maintenance issues promptly, preventing small problems from becoming major fuel efficiency drains.
12 Tips to improve semi truck fuel economy
These fuel-saving practices are widely supported by trucking research and fleet performance data and can help drivers reduce fuel spend without changing lanes or loads. Each tip addresses specific factors that impact fuel consumption and offers practical steps any driver can implement immediately to start saving money at the pump.
1. Reduce your cruising speed
Fuel efficiency peaks around 55-65 mph, and fuel burn increases rapidly at higher speeds. Industry research shows that driving at higher speeds significantly reduces fuel economy, with fuel consumption increasing substantially when driving 75 mph compared to 65 mph.
Every 5 mph you drive over 60 mph is equivalent to paying extra for diesel. While slower speeds mean longer trip times, the fuel savings often outweigh the time cost, especially when combined with route planning tools that help you avoid traffic delays.
2. Maintain steady seeds and avoid rapid acceleration
Consistent throttle use reduces fuel burn and drivetrain stress. According to the U.S. Department of Energy, aggressive driving, including rapid acceleration and braking, can lower fuel economy by roughly 10% to 40% in stop-and-go traffic and 15% to 30% at highway speeds, while sensible driving habits can improve fuel economy by 10% to 40% compared to aggressive driving patterns.
Cruise control helps maintain consistent speeds on flat terrain and gentle grades, but drivers should disengage it on steep hills where manual throttle control allows for more efficient power management. The goal is to minimize unnecessary speed variations that force the engine to work harder than necessary.
3. Minimize idling whenever possible
Idling can burn close to one gallon of diesel per hour with no productive work being accomplished. The U.S. Department of Energy reports that excessive idling wastes billions of gallons of fuel annually across the trucking industry, representing both environmental waste and unnecessary operating costs.
Modern trucks with auxiliary power units or battery-powered climate control systems can provide comfort without running the main engine. When idling is unavoidable due to extreme weather or operational requirements, limiting idle time to essential periods and using engine shutdown when possible can save significant fuel over the course of a year.
4. Check tire pressure regularly
Underinflated tires increase rolling resistance and fuel consumption by forcing the engine to work harder to maintain speed. The North American Council for Freight Efficiency found that tires underinflated by 10 psi can increase fuel use by about 0.5-1.0%, making regular pressure checks one of the simplest maintenance tasks that directly protects efficiency.
Tire pressure should be checked at least weekly when tires are cold, before driving. Seasonal temperature changes can significantly affect tire pressure, with cold weather causing pressure to drop and potentially creating efficiency losses if not corrected promptly.
5. Use low-rolling-resistance tires
Low-rolling-resistance tires are designed to reduce the energy lost as heat when tires flex during rolling. The Environmental Protection Agency reports that switching to these specialized tires can improve fuel economy by more than 3% compared to standard tires, making them one of the most cost-effective equipment upgrades available.
While low-rolling-resistance tires may cost slightly more upfront, the fuel savings typically pay back the investment within the first year of use. Many carriers now specify these tires as standard equipment on new trucks and as replacement tires on existing equipment.
6. Improve aerodynamics with add-ons
Side skirts, cab fairings, gap reducers, and trailer tail devices can significantly reduce aerodynamic drag by smoothing air flow around and behind the trailer. Industry testing shows that aerodynamic packages deliver measurable fuel economy improvements at highway speeds, with benefits increasing as speed rises above 55 mph.
The benefits of aerodynamic devices increase with speed, making them particularly valuable for long-haul operations on highways. Drivers using the OTR Fuel Card can save even more by combining fuel discounts with aerodynamic improvements for maximum cost reduction.
7. Reduce unnecessary weight
Extra weight reduces MPG, especially on grades where the engine must work harder to move heavier loads uphill. ATRI research shows that reducing truck weight by 1,000 pounds can improve fuel economy by approximately 0.25%, which may seem small but adds up to meaningful savings over thousands of miles.
Evaluate your truck for unnecessary equipment, tools, or materials that add weight without providing value. Empty fuel tanks that aren't needed, remove unneeded spare parts, and avoid carrying excessive amounts of supplies that could be restocked more frequently. Read about how much a gallon of diesel weighs for further considerations.
8. Optimize load distribution
Balanced loads improve handling and reduce rolling resistance by ensuring even weight distribution across all axles and tires. Properly distributed loads allow tires to wear more evenly and operate more efficiently, reducing the energy required to maintain speed and protecting your equipment investment.
When loading, place heavier items low and centered in the trailer to lower the center of gravity and improve stability. Uneven weight distribution can cause some tires to work harder than others, increasing rolling resistance and reducing overall fuel efficiency.
9. Shift efficiently and keep RPMs in the optimal range
Modern automated manual transmissions handle shifting efficiently, but manual transmission operators should shift to keep engine revolutions per minute (RPMs) in the most fuel-efficient range. Most diesel engines provide the best balance of power and efficiency when RPMs stay between 1,200-1,500 during highway cruising, though this varies by engine model.
Upshifting as early as possible without lugging the engine and downshifting only when necessary helps keep engine speeds in the efficient range. Progressive shifting techniques that skip gears when possible can also improve fuel economy by reducing unnecessary engine speed increases.
10. Plan more efficient routes
Route planning can reduce fuel waste by cutting stop-and-go driving, detours, and idle time. According to FleetOwner, fleets are optimizing routes for various outcomes, including finding the best possible fuel pricing, improving delivery time, cutting idle time, reducing driver fatigue, and avoiding congestion. Smart route selection helps drivers minimize time spent in low-speed conditions and reduce unnecessary miles that add fuel costs without generating revenue.
Using tools integrated with the OTR Mobile App helps drivers find optimal routes and locate discounted fuel stations along the way. Smart planning means fueling at the right locations and times to maximize savings while avoiding detours that waste fuel.
11. Use high-quality diesel and fuel additives when needed
High-quality diesel with proper detergent packages helps keep fuel systems clean and operating efficiently. Fuel additives can help in specific conditions like extreme cold weather or when storing fuel for extended periods, though gains from additives are typically modest for most operations.
Premium diesel may cost slightly more per gallon but can provide better fuel economy and reduced maintenance costs over time. However, the benefits must be weighed against the price difference to ensure overall cost savings.
12. Keep up with regular truck maintenance
Clean air filters, proper wheel alignment, and well-maintained engines all contribute to optimal fuel economy. Industry experts note that neglected maintenance can reduce fuel economy by 10% or more through increased friction, poor combustion, and mechanical inefficiencies.
Regular maintenance schedules should include checking and replacing air filters, maintaining proper wheel alignment, inspecting and replacing worn components, and ensuring emission control systems operate correctly. Carriers with reliable cashflow from freight factoring can invest in preventive maintenance that protects fuel efficiency over the long term.
Fuel economy benefits for fleets and owner-operators
Improved fuel economy delivers multiple benefits beyond immediate fuel cost savings. Lower operating costs improve profitability on every load, making your operation more competitive and sustainable regardless of market conditions.
ATBS reports that fleets achieving just one additional mile per gallon save thousands of dollars per truck annually. These savings compound over time and across multiple vehicles, creating significant competitive advantages for carriers who prioritize fuel efficiency.
Key benefits of better fuel economy
- Lower operating costs - reduced fuel spend improves margins on every load
- Fewer breakdowns and less maintenance - efficient operation reduces engine stress and extends component life
- Higher profit margins - improved efficiency translates directly to better bottom-line performance
- Longer engine lifespan - operating engines in optimal ranges reduces wear and extends service intervals
Carriers using OTR Clutch for business banking can easily track fuel expenses and measure efficiency improvements over time, making it simpler to identify trends and verify the impact of fuel-saving initiatives.
Frequently asked questions
What is the average fuel economy for a semi truck?
The average fuel economy for Class 8 semi trucks typically ranges from 5-8 MPG, with modern trucks reaching higher numbers under optimal conditions.
What speed gets the best fuel economy in a semi truck?
Most semi trucks achieve optimal fuel economy between 55-60 mph on flat terrain.
Do fuel additives improve fuel economy?
Fuel additives can provide modest improvements in specific situations, like extreme cold weather or when cleaning fuel systems, but gains are typically limited.
How much fuel does a semi truck burn while idling?
A Class 8 semi truck typically burns 0.6-1 gallon of diesel per hour while idling, depending on engine size and load.
What maintenance items affect fuel economy the most?
Tire pressure, air filter condition, wheel alignment, aerodynamic equipment condition, and emission system performance have the largest impact on fuel economy.
Your path to a more fuel-efficient trucking operation
Driving habits, maintenance practices, and aerodynamic improvements all play direct roles in improving semi truck fuel economy. Even small changes like reducing cruising speed by 5 mph or checking tire pressure weekly can reduce fuel costs and help drivers keep more of what they earn mile after mile.
True Non-Recourse Factoring protects you from non-paying brokers when you're working with brokers approved to factor with OTR. With Truly Instant Funding, get paid within minutes of invoice upload, 24/7/365, to any bank account. Plus, the OTR Fuel Card delivers average savings of $0.50 per gallon at 2,500+ in-network locations nationwide.
Get Started with OTR Solutions and start maximizing your fuel efficiency today.
