Do Truck Bed Cover Increase Gas Mileage

The question of whether a truck bed cover actually increases gas mileage is a perennial debate among truck owners. The answer, like many things in automotive engineering, isn't a simple yes or no. It's a nuanced issue dependent on a variety of factors including vehicle aerodynamics, driving style, speed, and the specific type of bed cover used. Let's dive into the science and real-world experiences to get a clearer picture.

The Aerodynamic Argument: Reducing Drag

The core argument for improved fuel economy with a truck bed cover revolves around aerodynamics. Without a cover, a truck bed creates a pocket of turbulent air behind the cab, increasing aerodynamic drag. This drag acts as a resistance force, forcing the engine to work harder to maintain speed, and consequently, consuming more fuel.

A bed cover, proponents argue, smooths out the airflow over the truck, reducing this turbulence and drag. This streamlined airflow allows the truck to slip through the air more efficiently, requiring less engine power and improving gas mileage.

How Significant is the Aerodynamic Impact?

Several studies and anecdotal evidence suggest that the aerodynamic benefit is real, but its magnitude can vary considerably. Wind tunnel tests conducted by various aftermarket companies and independent researchers have demonstrated that a bed cover can reduce drag coefficient (Cd) – a measure of how well an object moves through air. Reductions in Cd typically range from 5% to 15% depending on the cover's design and the truck model.

However, translating this Cd reduction into tangible MPG gains on the road is complex. The actual fuel savings depend heavily on driving speed. Aerodynamic drag increases exponentially with speed. The faster you drive, the more significant the impact of improved aerodynamics becomes. Therefore, the benefit of a bed cover will be more noticeable on highways and interstates than in city driving.

Types of Truck Bed Covers and Their Aerodynamic Effects

Not all bed covers are created equal. Their design and construction significantly influence their aerodynamic properties.

Soft Tonneau Covers: These are typically made of vinyl or canvas stretched over a frame. While they can reduce drag compared to an open bed, their flexibility and potential for sagging at high speeds may limit their aerodynamic effectiveness.
Hard Tonneau Covers: Constructed from fiberglass, aluminum, or plastic, these covers offer a more rigid and streamlined surface. They are generally considered to be more effective at reducing drag than soft covers.
Retractable Covers: These covers can be rolled or folded away to provide full bed access. Their aerodynamic performance is generally similar to hard tonneau covers when closed. However, some designs may have gaps or imperfections that can disrupt airflow.
Truck Caps/Camper Shells: These fully enclosed bed covers significantly alter the truck's overall profile. While they can reduce drag compared to an open bed, their added weight and increased surface area may offset some of the aerodynamic benefits.

The height and shape of the cover also play a role. A cover that sits flush with the truck's cab is generally more aerodynamic than one that sits higher.

Weight Considerations: A Potential Offset

While bed covers aim to improve aerodynamics, they also add weight to the vehicle. This added weight can counteract some of the fuel savings gained from reduced drag. Heavier covers, such as those made of fiberglass or aluminum, will have a greater impact on fuel economy than lighter covers made of vinyl or canvas.

The extent to which weight affects fuel economy depends on driving conditions. In stop-and-go city driving, the added weight will be more noticeable as the engine has to work harder to accelerate from a standstill. On the highway, the impact of weight is less significant as the vehicle is already at a constant speed.

Real-World MPG Improvements: What to Expect

Despite the scientific arguments and anecdotal evidence, quantifying the actual MPG improvement from a truck bed cover can be challenging. Many factors beyond aerodynamics and weight influence fuel economy, including driving habits, tire pressure, vehicle maintenance, and weather conditions.

Most real-world tests and user reports suggest that a bed cover can potentially improve gas mileage by 1-2 MPG on the highway. However, some users report little to no noticeable difference, while others claim improvements of up to 3-4 MPG. These variations likely reflect differences in driving styles, vehicle models, and the specific bed covers used.

Example Scenarios:

Highway Commuter: Someone who primarily drives on the highway at consistent speeds will likely see a more noticeable MPG improvement from a bed cover than someone who primarily drives in the city.
Infrequent Hauler: If you rarely haul cargo in your truck bed, a bed cover can provide aerodynamic benefits without significantly impacting your hauling capabilities.
Heavy-Duty Truck User: On larger, heavier-duty trucks, the relative impact of a bed cover on overall fuel economy may be less noticeable due to the engine's larger displacement and higher fuel consumption.

Beyond Fuel Economy: Other Benefits of Truck Bed Covers

While the primary focus is often on gas mileage, truck bed covers offer several other benefits that should be considered:

Security: Bed covers provide a secure and lockable storage space for tools, equipment, and other valuables, protecting them from theft and the elements.
Protection from the Elements: A bed cover can shield cargo from rain, snow, sun, and wind, preventing damage and keeping items dry and clean.
Aesthetics: Many truck owners find that a bed cover enhances the appearance of their truck, giving it a cleaner and more streamlined look.
Increased Resale Value: A well-maintained truck with a bed cover may command a higher resale value compared to one without.

Conclusion: Is a Truck Bed Cover Worth It?

The decision of whether or not to invest in a truck bed cover depends on individual needs and priorities. While a bed cover can potentially improve gas mileage, especially on the highway, the actual savings may be relatively small and influenced by various factors. The other benefits of security, protection, and aesthetics may be more compelling reasons for some truck owners.

Before making a purchase, consider the following:

Driving Habits: How much highway driving do you do?
Budget: Bed covers range in price from a few hundred dollars to several thousand.
Desired Features: Do you need a lockable cover for security? Do you need full bed access?
Weight Considerations: Are you willing to sacrifice some payload capacity for aerodynamic benefits?

Ultimately, the best way to determine if a bed cover is right for you is to weigh the potential benefits against the cost and consider your specific needs and priorities.

Disclaimer: Results may vary. Fuel economy improvements are not guaranteed and depend on individual driving conditions and vehicle characteristics. It's advisable to keep accurate records of fuel consumption before and after installing a bed cover to assess its actual impact.