Although we don’t buy pickup trucks for mileage, still we would like to know if we can increase the gas mileage anyhow. When it comes to gas mileage, tonneau covers have been a topic of debate for increasing gas mileage. Therefore, I have asked my friends who have tested it to find out if it’s at all true.
Can truck cover increase gas mileage? With the tailgate down, the truck gives the least mileage. With the tailgate up it gives its usual mileage. With a soft tonneau cover, not the fiberglass lid, the truck does give more mileage.
How Much Gas Mileage You Get with Truck Bed Cover?
Using a soft tonneau cover does give noticeably better mileage but it depends on a lot of factors. If you have a soft cover such a vinyl cover, roll-up covers, or fleetside cover, it may give an extra mileage of 10-12%.
If you have a hard top such as a fiberglass lid, it will not give any extra mileage. Even if it reduces the drag, the weight of the lid counteracts the additional mileage.
With the tailgate up and no tonneau, the truck will give the usual mileage as claimed by the manufacturer. But with the tailgate down, you would be surprised to know that it actually reduces gas mileage.
Camper shells give the worst mileage. Although it will reduce the air drag it’s weight will reduce gas mileage significantly.
How Much Gas did My Friend Save?
My friend drives a Dodge Ram and lives in Colorado. He decided to test it for real on the road. First, we took off the tonneau cover and left the tailgate up. We took it to the road and drove at around 60 mph. We got around 21.3 mpg, which is close to what the manufacturer claims.
Next, we dropped the tailgate and drove back the same road at around 60 mph. We got around 20.2 mpg, which is much less than what the manufacturer claims.
The next day, we took the same road but with the tonneau cover installed. We drove at 60 mph and got 23.5 mpg as the gas mileage.
Why Tonneau Cover Saves You Gas?
A pickup truck is far from being the ideal aerodynamic vehicle. The tailgate is the primary reason of drag because of the cab. As air hit the top of the cab, the moment it reaches the end of the cab top, the air is forced down. Without the truck bed or tailgate, it would simply glide out but because of the bed and the tailgate, it does create a type of resistance causing your pickup to burn more gas to overcome that drag. The truck cab will be able to cut through the air drag but as the air hits the back of the tuck, the empty bed creates an air pocket. It creates an air pocket as well the air forces out the tailgate, creating a drag that would hamper your gas mileage.
To this, the intuitive answer would be to simply put down the tailgate, but on the contrary, it would use up more gas. A closed tailgate at least creates an air bubble that slowly circulates air on the bed; some of it rams into the tailgate and some just glide out freely. Putting the tailgate down creates even more drag as it pushes the air around the bed wall creating a pressure on the bed, thereby decreasing your truck’s gas mileage. Opening the tailgate breaks that air bubble for which the air that rushes over the cab also forces down the bed. This creates a lot of turbulence, thereby creating even more drag.
Installing the tonneau is the best way to ease out the drag. There is no option to create air pockets or is not pushed by the tailgate. The airtight design enables air to glide over the cover instead of creating a drag. This increases gas mileage by 10-12%.
Other Ways to Increase Gas Mileage
Pickup trucks have come a long way from being gas sucking machines to providing good fuel economy with its modern fuel management features and improvement in fuel injection systems. Even with all this, there is always an opportunity for you to increase mileage, which is exactly what we are going to discuss in the following content.
Here are a few things you can do to boost gas mileage of your pickup truck:
Keep fuel injectors clean
A clogged fuel injector is never good news and will definitely kill some of your pickup truck’s mileage. If it is heavily clogged you would need to contact a professional but for a minor clogging, you can use Techroline and Lucas Fuel System Cleaner. When the fuel injector is clean, it would spray a very fine mist of fuel which makes it easier to ignite thereby increasing your pickup’s mileage.
Keep Your Air Filter Clean
Next, you have to keep your air filter clean so that you get more airflow, thereby getting more mileage. If you like, you can also change the factory air filter with a cold air intake. Replacing your OEM filters with high volume air filter will increase fuel mileage to nearly half a mile per gallon of gas.
Keep Your Tire Pressure Right
Even with a minor decrease in tire pressure, you will lose a lot of gas mileage. Check the tires for the required pressure you need on them and if it’s 40 psi, you have to make sure the pressure is exactly 40 pounds. Usually in the summer, the pressure is kept a little low because the air expands in heat and in winter you need to add a little more air pressure.
How About Slowing Down
Probably the easiest way is to just stop speeding and drive at a good pace. Simply by slowing down from 70 to 60 miles per gallon, you will be saving a lot on gas mileage. It is primarily because of the drag that truck face at higher speeds.
Use a Programmer
You could use a programmer to increase horsepower and fuel mileage. They can decrease idle speed, adjust torque, prevent downshifting, etc. A popular programmer brand would be Bully Dog, which also has a lot of good reviews on the internet.
Don’t Lift Your Truck and Don’t Use High-Profile Tires
This is more like a way to prevent losing mileage. It’s a no brainer that putting oversized off-road tires and rims are really gonna hurt your mileage. These tires add an extra drag and raise the profile of the vehicle thereby creating even more drag. Next thing, you should not lift your truck as we already discussed it would create enough drag to lose your gas mileage.
Does all tonneau cover improve gas mileage?
No! Only tri-fold cover, roll up and sliding tonneau cover save mileage. Hard top or fiberglass lid will not save you any gas; although they prevent the drag, their weight compensates for any gas they could have saved.
Does loaded truck bed with a tonneau cover improve gas mileage?
Tonneau cover’s gas-saving capability can only be noticed or appreciated when the truck bed is empty. Which is good as your truck bed will be empty most of the time. However, with a loaded bed, the tonneau cover doesn’t make much difference. It could save you gas if you have the tonneau cover on with little cargo.
Does tonneau cover increase gas mileage in bad weather?
If you are driving in a storm or a blizzard, don’t expect your tonneau cover to do much. If it’s raining, the weight of the rainwater will kill your mileage points. So, is for snow! Frankly, you should be more worried by returning home safely than saving gas, when you are caught in bad weather.
So it’s settled that a ‘truck cover increase gas mileage by 10-12%’. However, it’s worth noting that when you will be hauling cargo the gas mileage will be pretty much same with or without the tonneau cover. Only if you are driving an empty truck with the cover on, will you notice any increase in the mileage which will most likely save your around $200 per year.