Tonneau cover and mpg

[ShadowsPapa]

How many people behind you did you kill or seriously maim during this experiment? It's possible that they were a-holes; I hope so.

It was mostly garbage stuff that was tossed in the back that was forgotten about. cans, styrofoam cups - made it all the way home. Leaves got blown to the front of the truck. You know, go to the swap meets or races and cans and cups get tossed into the backs of trucks. You get home and find the stuff sitting up in the front of the box when you get home.

The board - no experiment. Small pieces of quarter inch OSB blew out the back on a rural road. Not one to leave stuff like that, I stopped and picked it up and tossed it inside. Forgot it was back there after a project.

I have seen people hauling plywood in a short box pickup, tailgate down, the stuff is sucked up and lifted right out of the truck. That's scary.
I always carried ratchet straps and secured such loads of OSB or plywood tight to the tail gate.

When I haul fenders, hoods, that sort of thing - always strap accordingly. Especially if near the back half of the box. Up front it takes less strap, at the rear, more.

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[ShadowsPapa]

Right. All what I said above was for a fairly-short box. A longer box would have different dynamics.

A box as short as the JT has should be very different than any full-size, even other mid-size trucks.
It's a totally different animal than anything else most of us have had. No comparison.

 

[MarineHawk]

It was mostly garbage stuff that was tossed in the back that was forgotten about. cans, styrofoam cups - made it all the way home. Leaves got blown to the front of the truck. You know, go to the swap meets or races and cans and cups get tossed into the backs of trucks. You get home and find the stuff sitting up in the front of the box when you get home.

The board - no experiment. Small pieces of quarter inch OSB blew out the back on a rural road. Not one to leave stuff like that, I stopped and picked it up and tossed it inside. Forgot it was back there after a project.

I have seen people hauling plywood in a short box pickup, tailgate down, the stuff is sucked up and lifted right out of the truck. That's scary.
I always carried ratchet straps and secured such loads of OSB or plywood tight to the tail gate.

When I haul fenders, hoods, that sort of thing - always strap accordingly. Especially if near the back half of the box. Up front it takes less strap, at the rear, more.

I was just kidding about killing/maiming people.

 

[eaglerugby04]

I put in a diamondback HD on mine. I can say for sure that a 100lb+ cover did not lower my mileage at all. My MPGs have seem to went up some, but I honestly could not have told you if it was because of the cover or because I figured out the quirks of the truck a little better (how to use auto stop and optimize cruise control mostly.)

 

[Beowulf85]

I put in a diamondback HD on mine. I can say for sure that a 100lb+ cover did not lower my mileage at all. My MPGs have seem to went up some, but I honestly could not have told you if it was because of the cover or because I figured out the quirks of the truck a little better (how to use auto stop and optimize cruise

Keeping the avg mpg up is def a art form.

 

[eaglerugby04]

So true, it is almost like a game. I swear the way the bar is on the Prius they made it into an actual game. 6 years with that car and I know every trick to boost the MPG, and almost all of them work on the Gladiator luckily.

 

[Beowulf85]

Game on !

 

[Br4hm4]

I have noticed a very slight improvement...mostly on the highway. Day to day driving seems to be about the same.

 

[Klutch]

Pickup truck aerodynamics are indeed strange. Back in the "bad old days", my dad would drive his truck with a can of beer between his legs. When the can was empty, he would hold it outside the door window and let go. The empty can would get sucked right into the bed. Multiple empty beer cans would stay in the bed, right behind the cab, and never blow out at any speed.

I am in no way endorsing or approving of any of said behavior.

 

[MPETE]

Even in something as unaerodynamic as a jeep, the engineers have done every little thing they can to improve mpg straight out of the box. even on trucks. One of the big changes is how wide the top edge of the tailgate is. They used to be very narrow. if you look at say a 90's truck, the very top of the tailgate is an inch or two wide at most. If you look at a modern truck, especially a full size, the center of the top edge of the gate is usually close to 6" wide. That's not for looks, and while in the case of a Ford it does serve to house the hidden step, that's not the main purpose. It's main purpose is to give the air coming off the roof a "landing spot" as a way to smooth the airflow coming off the roof.
Another factor is it basically it comes down to the fact that the bed is too short for it to really matter. on the vast majority of 5 or 6 foot beds this is usually the case. A member of an eco-modder forum did some tonneau cover vs open bed vs tailgate up/down testing and determined that somewhere between 6 and 7 feet is the area where a tonneau cover begins to play a role in aerodynamics. And in those tests on an 8 ft bed, he found that simply adding a small cover over the last 3 feet or so of the truck bed was enough to improve the aero, and contrary to what you may think, air did not get under the cover enough to change results. So it didn't act like a parachute as you would expect.

As for the Gladiator specifically, especially a soft top, the air coming off the flappy material is already going to be so disturbed there's not going to be much you can do to help anyway. and if the top is down, well forget it.

 

[Beowulf85]

either my truck finally broke in or the literider access cover I put on is helping. Def been easier to keep my above it's current average mpg. Thinknits the break in though hit 1500 miles day ago.

 

[BAT]

I haven't seen any difference in my mileage with the hard trifold on the bed nor any difference in MPG going from Hard top to Soft Top.

 

[Vegas_Blue]

Anyone notice much of a difference in mpg when useing a tonneau cover? If so how much?

I haven’t noticed any difference

 

[Capricorn]

No noticeable difference with the soft tonneau after it was installed. And I mostly drive on the freeway.

 

[ShadowsPapa]

See mythbusters videos on youtube. They did an update test.

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