Ok, we all know that this is a heated debate. I drive to school and work with mine down. Although I read all over the place that you get better gas mileage with it up. Common sense tells you a big 60" by 24" rectangle sticking into the airflow will increase parasite drag. Not only can I feel a lighter gas pedal on the highway compared with it up, I'm also a pilot and something comparable to having the tailgate up is dropping flaps on landing. Now those little itty bity things slipping into the slipstream really slow you down for landing. What your input? Anyone have any scientifical evidence?


-Alex

 

Only downside to having mine down is that I cant show off my perty new '07 V6 badges! And also don't want people running into mine with it sticking out when I arrive at school. We have a small parking lot and I pull it up when I get there. But once I get my Fire and Ice in, I'll be putting mine up when I'm on the road

 

they did this on mythbusters. they prooved you get better miliage with it up. when its up, a vortex is created in the bed when you drive and the air basically comes over the top of the cab and straigt over the top of the tail gate because of the air swirling around in the bed. i know its true because when i leave empty water bottles in the back of my truck, they fly up right behind the cab, and not by the tail gate

 

didnt a tonneau give the best gas mileage though? i know what your talking about, my pedal feels alot lighter when my gate is down. my gas mileage is so bad though, it doesnt really make a difference for me either way

 

Do a search on the subject, been discussed thoroughly, several times.

 

Up for a shorter box, down for a longer box. Keep in mind if you hit a bump just right with it open and one side of the truck drops before the other you can loose your tailgate. I am not sure what they are going for these days but it would take awhile to recoup by saving 1-2 mpg, I leave mine up as much as I can.

 

myth busters has done this already better with it up. creates a tornado like wind tunnel in the back up the bed air circulates around and around. tailgate down, creates down force to the truck

 

x2 Leave it up...

 

I have done this experiment too. drove from Maine to North Carolina several times down I-95. Tailgate up definitely gave me better mileage. Remember Bernouli's principle and an airfoil? the tailgate up creates an air pocket ( low pressure) and allows the rushing air to just move over the bed, versus leaving it down which creates no air pocket and the air hits the tailgate, causing downward pressure and more drag. myth confirmed!! My $.02

 

I disagree with your saying it is your 2 cents. Its a fact, so wouldnt that make it worth more?

 

Yeah proven fact that tailgate up results in better gas mileage.

I have a tonneau, which gave me a ~1MPG increase over tailgate up, so the best for gas mileage is:

Tonneau > Tailgate Up > Tailgate Down.
You can also google for more info and actual data on it.

 

Wanna keep the gate from coming off on pre 04's.
Take a hose clamp, the type you screw tight.
Put it on the pivet cover that has the opening on it. It;s kinda tricky and you have to have the gate on plus you have to posistion it so it allows it to close.
Someone tried, I say tried, to steal mine. Naah still there.
On my '07 I got the Leer 700 top and had them install a lock so that when the doors are locked not only the topper locks but the gate locks too.

 

http://www.nrc-cnrc.gc.ca/highlights...uplands_e.html

 

Up. As was said, it was proven on Mythbusters that tailgate up gives you better milage.

 

It is also a well known myth that driving with your windows up & the AC on is better for your mileage because of the drag created by wind blowing in the windows.

But the MythBusters proved that it was better to just drive with the windows down because the AC used up so much gas. That was on an open track, not in a wind tunnel or on a dyno.

MythBusters has to take two identical trucks, run them against each other, one with the tailgate up & the other with the tailgate down. With a control of equal distance, say 120 miles or 2 hours worth of driving, then see which truck burned off more fuel.