Will you get better fuel mileage with the tailgate up or down, during highway speeds?....
Dan /FT

 

Keep it down the tail gate is like a parachute

 

I actually tried this once and I think I got around 3/10 of a mile more per gallon with it down.....not really a big deal, although I guess over the life of the vehicle it could add up.

 

I agree with better gas mileage, but I hate to hear that thing bounce around...I would remove it, or go with a Tonneau cover.....

 

I thought having it half-way open was the best for gas mileage?? Isin't there a company that sells a kit to do just that?

Kinda reminds me of when I read in Car & Driver that a Mustang Cobra with a wing was measurably slower than one without down the 1/4 mile, didn't do much for downforce either!

 

I have read that the air flow will create a swirl from the rear window and the gate. This allows a greater air flow over the truck bed. Think about why they tend to have the low front rake.

 

UP.

The tailgate helps creates a high pressure area (slow moving air) behind the cab which diverts the low pressure air (fast moving) up and over it.

Tailgates are not parachutes. Nor do they act like one at speed. They are too close to the truck for that to happen. Now, if they were about 5 feet behind the truck, well...

 

This was teste years ago, a mag drove a truck across country, they alternated, filling the tank and driving till empty with the gate up then down. When everything was totaled up they averaged .5 MPG better with the gate up. I think the total miles driven, all non stop, were 3000+.

On a side note I just read in Truck Trend an article about what the MFG’s were doing to improve MPG. Ford said the reason every truck and SUV had running boards was because they helped control the air going under the truck and improved MPG. No figure was given as to how much though.

 

Ken,
I like the "Bullwinkle Badge"
Bert

 

I love skydiving.....

 

Tailgate up/down - no difference at all with my truck... Of course I have a camper shell!

I have heard rumor of extra flex/stress to your sidewall joints if you don't have your tailgate up. I think this would only apply when running down bumpy roads (off-roading) and not when trying to get good mileage on a smooth big roads.

Just a thought.

Edmo

 

There have been studies that have proven you get better mileage with the tailgate up and some with it down. I don't think it really makes any difference at all. If you're worried about tweeking that extra 1/100 MPG maybe you should own a ricer.

 

Your truck cab front rake is designed areodynamicaly to lessen the braking effect of our beast against the wind. This rake allows the beast to slip more efficently thru the air at higher speeds. More slip...less drag...better milage.

As the truck moves thru the air a "bubble" effect is created in the bed behind the cab area. This bubble typically has a higher profile than the cab, thereby, directing the airflow up and away from the tailgate area. It is this bubble that keeps our "stuff" dry in the rain when you put said stuff directly behind the cab. It ain't stayin" dry just because you are going fast.

Remember, especially with design guys, everything has a purpose and there is a purpose for every thing.

Modifications such as tool boxes, bed covers etc...actually degrades the shape and therefore, the purpose and performance of this bubble.

With all that said...without mods you should get optimal MPG (always relative to your driving style) with the tailgate in the up position. The down position can also disrupt the shape & size.

But what do I know...I have a toolbox and a cover on mine. If I was worried about fuel efficency I would have bought a Pirus.

Naaaa.