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Truck bed cover and gas milage

I have been thinking of getting a cover for the ned of my truck. However, I don’t want it to affect my gas milage. Does anyone know if it will? Thanks.

Usually, the people claiming it will save gas are the people who make and sell the bed covers. Otherwise, I doubt you will find anyone making those claims.

If it is a camper top you may loose a couple of miles per gallon. I got a trac top ~ more or less a retractable tanneu cover and had no change in gas mileage.

The bed cover won’t change your fuel economy, but it will improve your highway ride. I think it improved mine anyway, even though it may be due to the extra weight I put in the back. If you want to bring your family on a trip along with four big suitcases when snow or rain is expected, I recommend a cover.

I have an 02 GMC Sierra extended cab with the 4.8 engine, 4WD with automatic transmission, cruise control and air conditioning, with the serpentine belts to prove it. On my highway run from Ma. Rt 90 near Rt.84 I filled up and drove to the Augusta Me. area and got gas mileage that was darn good, for my truck, at 18.46 MPG. I’ll take that gas mileage under any circumstances, including possible inaccuracy. I drove on the freeway for about 40 miles before that fillup in Ma, so the truck was fully warmed up at the start of the mileage run.

I have the hard plastic cover with the lift struts.

I wished I could remember who did a test. If I remember there was a minimal increase in gas mileage. Less turbulence in the bed, maybe?

EDIT: Well I just did an Internet search, here is a link to one study:

Depends more on it’s height…even with top of cab made little or no difference for me.

Using a truck like a truck which may mean buying a cover (along with caps and racks) has always been my thought. If you start worrying about gas mileage too much with one and not using it like a truck, it may be time to trade or buy additional car.
Cover could help, but buy and don’t fret. Trucks stink relative to cars in mpg regardless and the change plus or minus should be insignificant.

 It depends on the truck and the cover.  It is the same with the tail gate up or down question.  Wind resistance questions are not easy to predict.  The only way of making sure is to try it out I a wind tunnel or on the road.  

 It seemed counter intuitive but for most pickups having the tail gate up gives better mileage.

Unfortunately, that study was funded by the Specialty Equipment Market Association. This is an association of people who sell these things. They have a conflict of interest.

I would be interested to see a study not funded by people with a conflict of interest.

I’ve read a few tests on this issue and with the exception of those performed by the tonneau cover manufacturers they all say "no difference’.

I’ve also seen some years back the results of a wind tunnel study on pickups using smoke trails. The area in the bed becomes a vortex spinning aft on top and fore on the bottom. This vortex presents a low pressure center with a high pressure boundry. The air going over the cab slides down the aft-flowing high pressure boundry and over the top of he tailgate.

Tonneau covers don’t alter the effect, they only alter the dimensions of the vortex.


I guess the point is; Don’t put one on if gas milage is your only reason. I have one of the easy lift styles. It looks good, keep stuff in the bed dry and inthe bed and it easy to lift and take on and off.

Gas milage for me never came into it.