How to Drive a Truck for Maximum Fuel Efficiency

As a truck driver, there are some expenses you know are going to cost you the most from month to month. Unlike many of your other biggest expenses, fuel is one that you have a lot of control over. Other than choosing stops with the lowest net cost of fuel and adding aerodynamics to your truck, there are many other strategies you can employ while driving in order to spend less on fuel. These strategies are controlled between your ears and are the decisions you make and the habits you form when driving your truck. Here are a few tips for how to drive your truck to maximize fuel efficiency and put thousands of dollars back into your pocket.

How to Drive a Truck to Fill Up Less

Drive Slower

Truckers don’t get much encouragement from their shipper or receiver to get somewhere slower. But speed is the number one reason for increased fuel consumption and reduced profits. The faster you go, the more fuel you are going to use. In fact, a simplified rule of thumb is every mile per hour driven over 60 mph reduces fuel economy by one-tenth of a mile per gallon.


The typical argument against driving slower is that you can make better time by driving faster, and therefore make more money. For the purpose of this article, we are talking about how you can save money on fuel by driving slower. Here is a hypothetical example of how much more a truck driver will have to drive per year to make up the additional fuel cost of driving faster.


Compare one driver running at 70 mph getting 6 mpg and another running at 60 mph getting 7 mpg. Over an hour, driver A is 10 miles further down the road than driver B, but at $3.15/gal., he’s spent around $9.75 more to go those 10 miles in the same amount of time.


That might not seem like much money, but the impact over an entire year is significant. If you drive 110,000 miles per year and average 6 mpg vs. 7 mpg because you drive faster, you will spend $8,250 more on fuel.


Find the Sweet Spot of Your Engine

The “sweet spot” is the most efficient RPM to run your engine. Running your engine in its sweet spot requires that you drive at a constant speed that is usually slower. If your engine is working harder in order to drive at a certain speed, more fuel is going to be used. Modern engines are designed for high torque at low RPMs. The lower the RPMs your engine is running to pull the load the less fuel it has to burn to create energy and overcome all the forces acting against your truck and load (like gravity, rolling resistance, mechanical resistance, and air pressure).


The trick is using torque, not horsepower to pull your load. Pulling with horsepower means you are using more energy and therefore burning more fuel. Pulling with torque means you are sustaining your speed without having to overwork the engine.


In general, a good sweet spot tends to be between 1250 - 1350 RPM. The number not to exceed is 1500 RPM. Every truck engine and drivetrain spec varies, which is why your owner’s manual should list the ideal range for your engine. If you don't know it and aren’t able to find it in the owner’s manual, make sure to contact your dealer and they can let you know peak horsepower and peak torque at a specific RPM.


Keep in mind that there are external factors that are going to affect your sweet spot. The main takeaway is that the lower the RPM, the less fuel your engine will consume.


Be Smart with Braking

As you are driving, it's inevitable that you are going to have to use your brakes. In fact, there are going to be times you need to forcibly apply your brakes to be safe. However, there are ways to drive so you don’t have to use your brakes as much.


The problem with braking in terms of fuel efficiency is that every time you touch the brake you lose energy -- you have to accelerate and burn energy (fuel) to get back up to speed. In order to accelerate to get back up to speed, you must put your foot down on the accelerator pedal and work the engine which burns additional fuel.


Two of the best ways to reduce braking are to anticipate changes in traffic and follow at an extended distance. By making this a habit, you’ll leave plenty of distance between you and the vehicle in front of you. You won’t have to brake every time the car in front of you does. Also, if a vehicle pulls in front of you, there is plenty of room for that vehicle if they slow down. This way you won’t have to slam on your brakes to prevent rear-ending them.


Stay in a Higher Gears

For those that have experience driving trucks, shifting gears is second nature. However, some may have not thought about shifting gears in relation to fuel efficiency. You’re driving a truck -- not a race car. Every time you hear and feel your RPMs go up you’re burning excess fuel. That’s fine at the race track on Sunday afternoon, but it’s not fine if you’re working to maximize your trucking business’ profits over the next twelve months.


At a consistent speed, the lower the gear, the higher the RPM. This means the harder the engine has to work to go that speed, which also means the more fuel is being burned. Paying attention to your gears to maximize fuel efficiency is similar to finding the engine’s sweet spot. This is because the gear you are in determines how much the engine is working. Remember...modern engines are built for high torque at low RPMs.


When you are driving it’s better to shift to the next highest gear while still at a low RPM and in the sweet spot of the torque curve, rather than waiting for the engine to run up to a high RPM. Keep in mind, driving fast in a low gear consumes about 45% more fuel than is needed.


Additional Tips

Think about Your Momentum

In order to go forward, you don’t always need to have your foot pressed all the way down. If you need to accelerate, think about speeding up gradually. Be aware when going up and down hills and try to safely build momentum going downhill so that you don’t have to use so much fuel to get up the next hill.


Utilize Cruise Control

If you are on a stretch of highway that isn’t busy, don’t be hesitant to use cruise control. Using cruise control can help you go at a consistent speed and keep you from doing unnecessary accelerations and decelerations. Cruise control can actually save you up to 6% in fuel consumption.


Cut Out of Route Miles

Use your atlas or GPS to take the shortest and quickest reasonable route with the least stops to your destination. If you need to stop, try to plan that stop for filling up, going to the restroom, eating, and anything else you need to get done in order to avoid going off route to stop again. Typically 6-10% of owner-operators’ miles are out of route. Try cutting this in half by really thinking about your stops and staying consistent with your route.


Minimize Idling