Do Tonneau Covers Really Save Gas?

 

Do tonneau covers really save gas? It is one of the most searched, debated, and oddly entertaining questions in the pickup truck world.

It makes sense. Gas is expensive. Trucks are not tiny. And if adding a truck bed cover could improve MPG, reduce drag, and save money every time you drive, every pickup owner would want to know.

The honest answer is this: a tonneau cover may improve fuel economy a little in some conditions, but the savings are usually modest and not guaranteed.

That does not make the question useless. It makes it more interesting. MythBusters tested it. SEMA studied tonneau covers in a wind tunnel. Consumer Reports ran a real-world fuel economy test. Pickup owners have been arguing about the results ever since.

Want the basic definition first? Start with What Is a Tonneau Cover?

Why People Think Tonneau Covers Save Gas

The theory is simple.

An open pickup bed creates airflow behind the cab and around the tailgate. A flat cover changes how air moves across that space. If airflow gets smoother, drag may go down. If drag goes down, the engine may not work as hard. If the engine works less, fuel economy may improve.

That is the basic argument behind tonneau covers and gas mileage.

The problem is that real driving is not a clean laboratory test. Wind, hills, tire pressure, cargo weight, traffic, temperature, speed, driving habits, and accessory weight all matter too.

So yes, aerodynamics matter. But they are only one part of the MPG puzzle.

Why MythBusters Is a Big Part of This Question

MythBusters deserves a major place in this article because it brought the pickup tailgate and fuel economy debate into everyday conversation.

A lot of drivers first heard the question from Adam and Jamie. Should the tailgate be up or down? Does a hard cover help? Does a mesh tailgate work better? Does removing the tailgate make a difference?

Those questions stuck because they feel like real pickup-owner questions. They are also exactly the kind of questions people search before buying a tonneau cover, truck bed cover, cap, or cargo system.

You can watch the official MythBusters clip, Is a Truck More Efficient with the Tailgate Down?, where Adam and Jamie put the tailgate theory to the test.

The big value of MythBusters is not that it settles every truck, every cover, and every driving condition forever. It is that it shows how pickup aerodynamics are not always obvious.

The answer that feels right in your head is not always the answer the airflow gives you.

The MythBusters Revisit

The MythBusters revisit is even more important because the show came back to the subject after viewers kept pushing the question.

The MythBusters Episode 64 summary covers the revisit where Adam and Jamie tested several pickup configurations, including tailgate up, tailgate down, no tailgate, hard top, and mesh tailgate.

That revisit is one reason this topic keeps getting traffic. It is not just a dry fuel economy question. It is a consumer mystery with a memorable TV experiment attached to it.

In that revisit, the mesh tailgate performed best in their test. The hard top, no tailgate, and standard tailgate-up setup were fairly close. Driving with the tailgate down performed worst.

That result challenges the old belief that lowering the tailgate automatically saves fuel.

For tonneau covers, the lesson is more measured. A hard cover did not create a dramatic MPG win in that test. But it also does not prove that every cover on every truck has no effect.

It proves the subject is more complicated than “cover equals savings.”

More YouTube Context on Tailgates, Airflow, and MPG

Video is useful for this topic because airflow is easier to understand when you can see it.

This related YouTube short on driving with the tailgate up or down shows why the old tailgate-down advice keeps getting questioned.

Another helpful consumer video is Autoblog’s Ford F-150 tailgate myth video, which explains the airflow idea behind keeping the tailgate up.

The point is not that every video agrees perfectly. The point is that pickup-bed aerodynamics have become a real consumer question. People watch these videos because they are trying to make practical decisions about their trucks.

That is exactly why this blog should address the topic directly.

The SEMA Wind Tunnel Study

The SEMA wind tunnel study also belongs in this article because it is one of the more technical tests tied directly to tonneau covers and drag.

In 2007, the Specialty Equipment Market Association tested multiple pickup trucks and several tonneau cover styles in a full-size wind tunnel. The goal was to measure whether covering the truck bed changed the coefficient of drag.

The SEMA 2007 wind tunnel study on tonneau covers and drag found that tonneau covers reduced drag on average.

The commonly cited result is about a 5.7% reduction in drag across the covers tested. The study connected that to a possible fuel-efficiency improvement around 1.8%.

That sounds promising, and it is.

But it needs context. A wind tunnel is controlled. Real roads are not. Drag reduction does not automatically translate into guaranteed MPG savings for every truck, every cover, and every driver.

Which Trucks Were Tested in the SEMA Experiment?

This is worth spelling out because older summaries of the study sometimes leave out the details.

According to the SEMA wind tunnel report, the final tested vehicles were:

• 2006 Ford F-150 with a 5-foot-5 bed
• 2005 Ford F-150 with a 6-foot-5 bed
• 2006 Dodge Ram 1500 with a 6-foot-5 bed
• 2007 GMC Sierra with a 6-foot-5 bed

SEMA originally wanted to use a Chevrolet Silverado, Dodge Ram, and Ford F-150 for the project. The report explains that vehicle availability and wind tunnel weight limits changed the final lineup. A 2007 Silverado was considered, but it was too heavy for the wind tunnel balance because of its configuration. A 2007 GMC Sierra was used instead.

That detail matters because it keeps the article accurate. If someone says the test used a Chevy Silverado, the more precise answer is that the Silverado was part of the plan, but the final test list included the GMC Sierra.

What Covers Did SEMA Test?

SEMA tested 13 different tonneau covers across the vehicles.

The mix included soft vinyl covers, folding covers, retractable hard covers, one-piece hard covers, two-piece hard covers, and fiberglass covers.

The study did not publish brand-by-brand results. That was intentional because participating companies were not trying to turn the study into a public product ranking.

That makes the SEMA study useful for a broad question: can a tonneau cover reduce drag?

It does not answer the narrower question: which exact cover will save the most gas on your exact truck?

What Did the SEMA Study Actually Show?

The key finding was that every tonneau cover tested improved coefficient of drag compared with the baseline truck configuration.

That is a strong point in favor of the aerodynamic theory.

But the report also cautioned that real-world fuel economy depends on more than drag. Rolling resistance, drivetrain efficiency, vehicle weight, cover weight, speed, and real road conditions all affect MPG.

For shoppers, the practical takeaway is balanced.

A tonneau cover can improve aerodynamics. That does not mean every owner will notice big fuel savings at the pump.

What Consumer Reports Found

Consumer Reports adds a useful counterpoint because it tested the question in a more consumer-facing way.

In its pickup fuel economy test, Consumer Reports compared a Ram at highway speed with the tailgate up, tailgate down, and with a soft tonneau cover.

Their result was surprising. In that test, the soft tonneau cover did not improve fuel economy.

That does not mean every tonneau cover hurts MPG. It was one truck, one cover, and one test.

But it is a good reminder that big fuel-savings claims deserve skepticism.

If a product claims it will definitely pay for itself in gas savings, question that claim.

Driving Habits Usually Matter More

If your main goal is saving fuel, driving habits are usually a better place to start than any truck bed accessory.

The U.S. Department of Energy’s consumer guide to driving more efficiently explains that speeding, rapid acceleration, hard braking, excess weight, and aerodynamic drag can all affect fuel economy.

That is not as fun as buying a new truck accessory, but it is practical.

A tonneau cover may help a little in certain highway conditions. Slowing down, avoiding hard launches, keeping tires properly inflated, and removing unnecessary weight can make a more consistent difference.

Buy a bed system because it makes your truck more useful. Treat fuel savings as a possible bonus.

Speed Changes the Answer

Aerodynamics matter more at highway speeds than in stop-and-go driving.

If most of your driving is around town, running errands, school pickup, short commutes, and stoplights, a tonneau cover is unlikely to create a noticeable MPG change.

If you spend a lot of time on the highway, airflow may matter more. Even then, the result can be small enough that wind, traffic, tire pressure, hills, and daily driving variation hide the difference.

That is why one driver may swear a cover helped, while another sees no change at all.

Same idea. Different truck. Different commute. Different result.

Weight Matters Too

A light cover adds less weight. A heavy hard cover, large cap, or bulky retractable unit adds more.

Weight matters because your truck has to move everything attached to it. If a system slightly improves airflow but adds weight, the real-world fuel benefit may be smaller than expected.

This is especially important for smaller pickups. If you drive a compact or midsize truck, every bit of bed space, payload, and accessory weight can matter.

A truck accessory should make the truck more useful. It should not make the bed feel smaller, heavier, or harder to use.

So, How Much Gas Does a Tonneau Cover Save?

For most drivers, probably not much.

Some truck owners may see a small improvement. Some may see no noticeable change. Some may see different results depending on speed, truck shape, cover style, cover weight, cargo, weather, and driving route.

The best answer is not a universal MPG number.

The best answer is this: a tonneau cover may help in certain conditions, especially at highway speed, but the savings are not consistent enough to make fuel economy the main reason to buy one.

Buy one if it helps protect cargo, keeps gear out of sight, improves everyday bed utility, and fits the way you actually use your truck.

If fuel savings happen, great. But they should not be the entire sales pitch.

The Bigger Buying Question

Fuel economy is only one part of the decision.

A flat tonneau cover or truck bed cover can be useful when cargo stays below the bed rails. That is where flat systems make sense.

But pickup owners do not always haul flat cargo.

A cooler stack, generator, storage tote, kayak, bike, stroller, boxed appliance, lawn equipment, or jobsite material can rise above the bed rails quickly.

When that happens, a flat cover has to be opened, folded, rolled, retracted, removed, or left unused.

At that point, your cargo is exposed again.

If you are still comparing flat cover styles, read Choosing the Best Tonneau Cover for Your Pickup Truck.

Where Sawtooth STRETCH Is Different

Sawtooth STRETCH is not a tonneau cover. It is an Adaptive Cargo Management System, or ACMS.

That distinction matters.

Tonneau covers and truck bed covers are flat systems. Flat systems only work when cargo stays below the bed rails.

Sawtooth STRETCH is designed to protect and secure both small and large cargo. It adapts over taller, bulkier, and more irregular loads that a flat cover cannot continue to cover.

That gives truck owners increased capacity, more versatility, and fewer moments where the bed system gets in the way of using the truck.

For smaller pickup applications, see the Ford Maverick, Ford Ranger, and Chevy Colorado product pages.

Should You Buy a Tonneau Cover for Fuel Economy?

Not as the main reason.

A tonneau cover may slightly improve gas mileage in certain conditions, but the result is not consistent enough to make fuel savings the strongest buying argument.

A better reason to buy a bed system is cargo protection.

You want gear covered. You want tools out of view. You want luggage less exposed to weather. You want the truck bed to feel more useful. You want something cleaner than a tarp and bungee cords flapping in the wind like a defeated parade float.

That is the real value.

If you want a system that does more than sit flat over low cargo, read 10 Reasons You Need an ACMS.

Why This Matters for Smaller Pickups

Compact and midsize trucks make smart cargo management even more important.

A Maverick, Ranger, Colorado, Tacoma, or Frontier can be incredibly useful, but a smaller bed gives you less room to waste.

If a flat cover only works when everything stays low, the truck can feel limited the moment you carry taller cargo.

That is why Sawtooth focuses so much on adaptive cargo protection. It helps the truck keep doing truck things without forcing every load under a fixed flat surface.

The Bottom Line

Do tonneau covers really save gas? Sometimes, a little. Sometimes, not enough to notice.

MythBusters made the question famous because it challenged what a lot of pickup owners assumed. The SEMA wind tunnel study showed that tonneau covers can reduce drag. Consumer Reports showed that real-world MPG results can still be mixed. Energy.gov reminds us that driving habits often matter more than accessories.

If you are shopping for a flat tonneau cover, buy it mainly for cargo protection, appearance, and bed utility. Treat any fuel savings as a bonus.

If you want more versatility than a flat-only pickup truck cover can provide, Sawtooth STRETCH ACMS gives truck owners a more adaptive option. It protects and secures small cargo, adapts over larger cargo, and helps your pickup keep doing what a pickup is supposed to do.

Browse all available applications on the All Products page, or review common product questions on the Sawtooth FAQs page.

Load more. Haul more. Do more.