Our team at Let's Go Aero is always on the lookout for ways to enhance our customers' adventures. One common question we encounter is the choice between hitch carriers and rooftop carriers for transporting extra gear. Today, we're going to dive into this topic, focusing on the impact of these carriers on your vehicle's fuel economy.

Rooftop Carriers: The Common Choice, But the Right Choice?

Rooftop racks are a popular choice for many adventurers. They offer the flexibility to expand your vehicle's cargo capacity without the need to invest in a larger vehicle. Whether you're packing for a summer road trip or a frosty ski vacation, these storage boxes are a popular choice.

But hold onto your hats! Before you start singing rooftop carrier praises, don't overlook their impact on your vehicle's fuel economy. Mounting these carriers can significantly affect your vehicle's mileage. Various studies, including those by Consumer Reports, have shown that rooftop carriers can lead to a noticeable decrease in fuel efficiency.

How Much Does a Roof Rack Affect MPG?

The impact on MPG is considerable. Consumer Reports found that using a rooftop cargo box can reduce fuel economy by up to 25%. If your vehicle typically gets 20 miles per gallon, that could mean wasting up to 5 gallons of fuel with a rooftop carrier.

What is a Roof Rack?

Roof racks are mounted on the roof of a vehicle, providing a platform to carry various items. They are commonly used for carrying bikes, kayaks, and gear (inside enclosed boxes).

Pros:

• Increased cargo space
• Flexibility for vehicles without hitches

Cons:

• Increased aerodynamic drag
• Potential height restrictions
• Significant impact on fuel efficiency

What is a Hitch Rack?

Hitch racks are attached to the vehicle's rear hitch receiver, extending the vehicle's cargo capacity. They are commonly used for carrying bikes, coolers, and camping gear (inside enclosed cargo boxes).

Pros:

• Easier loading and unloading
• Less impact on vehicle height
• Better fuel efficiency compared to roof racks

Cons:

• May require a hitch receiver

Comparative Analysis of Fuel Efficiency Impact

To understand how different types of racks affect fuel efficiency, it's important to compare the impact of roof racks versus hitch racks. Here’s a closer look at how each one measures up in real-world conditions.

Roof Rack vs. Empty Roof

Even without a load, a roof rack increases drag and reduces fuel efficiency. In fact, Car and Driver found a surprising 12% increase in mileage after removing just the crossbars from their test vehicle, a 2022 Kia Carnival. Around the same time, the U.S. Department of Energy's Office of Energy Efficiency & Renewable Energy (EERE) discovered that with a full rooftop cargo box, the reduction on fuel economy was as high as 25%. To put that into perspective, if you have a vehicle that averaged 20 miles to the gallon, you might see up to 5 gallons wasted with a rooftop carrier.

Hitch Rack vs. No Rack

On the flip side, hitch racks have a much smaller impact on fuel efficiency. The same EERE study mentioned above found that a rear cargo tray only reduced fuel efficiency by 1%.

Real-World Fuel Efficiency Tests

Real-world tests provide valuable insights into how roof racks and hitch racks impact fuel efficiency. Let's explore the findings from various studies to understand these effects better.

Overview of Studies and Tests Conducted on Fuel Efficiency with Roof Racks and Hitch Racks

A variety of studies have demonstrated the significant impact of roof racks on fuel efficiency. The Lawrence Berkeley National Laboratory highlighted the substantial drag caused by roof racks in 2015, which affects mileage that said lead to an excess "consumption that amounts to roughly 100 million gallons of gasoline a year". Additionally, Consumer Reports conducted tests on both a 2019 Nissan Altima sedan and a 2019 Toyota RAV4 small SUV, both traveling at 65 mph, and found a noticeable decrease in fuel efficiency when roof racks were used.

Summary of Key Findings from These Studies

Real-world tests consistently show that roof racks decrease fuel efficiency more than hitch racks. The tests conducted by Consumer Reports on the 2019 Nissan Altima and 2019 Toyota RAV4 confirmed a significant reduction in mileage with the use of roof racks. Furthermore, while anecdotal, we can't help but mention a recent GearDeck customer who shared that they experienced a 33% increase in fuel efficiency when using a hitch carrier instead of a rooftop box on long trips.

These studies, as well as reports from our customers, reinforce the overall findings that hitch racks are a more fuel-efficient option compared to roof racks.

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Choosing the Right Rack for Fuel Efficiency

When deciding between a hitch cargo carrier vs roof options, it's important to consider the impact on fuel efficiency, vehicle type, and frequency of use. Here are some key points to think about:

Type of Gear Being Transported

Consider the size and shape of the items you need to carry. Larger, bulkier items such as camping gear and bikes might be more aerodynamic when placed on a hitch rack rather than a roof rack. The shape and weight distribution of your cargo can significantly affect your vehicle's fuel efficiency, so choose the rack that best accommodates your gear.

Frequency of Use

Frequent users may benefit more from the fuel savings of a hitch rack. If you're regularly carrying extra gear, the lower drag of a hitch rack will add up to significant fuel savings over time.

Vehicle Type and Design

Some vehicles may be more aerodynamic and efficient with one type of rack over the other. For example, smaller cars might suffer more from the increased drag of a roof rack, whereas larger SUVs and trucks might handle the additional drag better but run into issues with overhead garage clearance. Consider how your vehicle's design interacts with the rack you choose.

Personal Preferences and Priorities

Weigh the convenience of each option against its impact on fuel efficiency. If you prioritize ease of access and installation, a hitch rack might be the better choice. Balancing these factors will help you make an informed decision that fits your needs and lifestyle.

Tips for Minimizing Fuel Efficiency Impact

To maximize your vehicle's fuel efficiency while using either a roof rack or a hitch rack, it's important to adopt some best practices. Here are a few tips to help you minimize the impact on fuel efficiency:

Roof Racks

• Remove the roof rack when not in use, and consider streamlined designs. Taking the roof rack off when it's not needed can help improve your fuel economy. Additionally, opting for a more aerodynamic, streamlined design can reduce drag and thus lower fuel consumption.

Hitch Racks

• Use a hitch rack for less impact on fuel efficiency and ensure it is properly installed and balanced. Hitch racks generally cause less aerodynamic drag compared to roof racks. Ensuring that the hitch rack is properly installed and that the load is evenly balanced can further minimize any negative impact on your vehicle's fuel efficiency.

Conclusion

Choosing between a roof rack vs trailer hitch can significantly impact your vehicle's fuel efficiency. While roof racks offer convenience for those whose vehicles lack a receiver hitch, they come at the cost of higher fuel consumption. Hitch racks, on the other hand, provide a more fuel-efficient solution for carrying extra gear. Ultimately, your decision should be based on your specific needs, vehicle type, and how often you use the rack. At Let's Go Aero, we're committed to helping you make the most efficient and practical choice for your adventures. Happy adventuring!