5er tailgate or not for better mpg?

bucky wrote:
I should have phrased the question differently. I am only referring to towing with the 5er attached. The tailgate would never be down in that situation, it would be gone or louvered. I am well aware of the insignificant differences when not towing, but there is a big ball of turbulence when I am towing, and I am looking for experience between the 2 with the same truck and the same 5er. That ball has to go somewhere when the gate is gone, so the question is where and to what effect. The truck is a 2WD quad cab long bed Dodge with a Jayco 345BHS 5er riding level.

I don't know if you're going to find what you're looking for. You're looking at maybe .5 mpg at best, but there's so many environmental variables out there that such a small gain could easily be invalidated. You'd probably need a wind tunnel to prove anything.

But if you're still looking for opinions, I would think that they're one in the same. Both will allow air to escape the bed which is a bad thing. The greater the airflow to the bed, the greater the drag potential via skin friction and or pressure drag. A complete tailgate will give you a protective bubble that helps reduce drag since most air will flow over the bed. Louvered will allow air to flow through and out of the bed increasing drag, but at a somewhat restricted flow because of the louvers. No tailgate allows for an unrestricted flow and an even higher drag potential, but you gain a weight reduction. Seems like a even trade off.

proxim2020 wrote:
I'm no aerodynamicist, but I'm sure there's lots of turbulent air that comes off of the 5th wheel and enters the bed. Turbulence = drag. If I had to guess, I'd say that the louvered or missing tailgate would only enhance the turbulent air flow. If there's actually a measurable difference I'd imagine that it would be very small. The front of the truck, gap between the trailer, and the trailer's rear end would have the most significant impact. If you could fashion some kind of boot to prevent the air from getting into the bed in the first place, then you might have some useful increase.

I haven't figured a practical way to do it but I've thought some sort of stretchy material from the back of the truck cab to the top of the 5er would have a real impact (sort of like the fairings on the top of semi-tractors). The problem is it would have to hook up quickly and easily and it would have to accomodate at least a 45 degree angle between truck and trailer (more would be better)

I would not be without the backup camera. Three different 5er TV's and never removed the factory tailgate.

Bucky, I have had a 5er tailgate for about 3 years. I did not get it for any mileage gain or loss. I just liked not having to mess with the tailgate during hookup. It holds things in the bed and I do have a tri-fold cover on my 8' bed. If I know we are not going anywhere in the winter months for a while, I pull off the 5er gate and put the stock gate back on.

N-Trouble wrote:
Ask yourself how many gallons of fuel would that new tailgate would buy. Personally I don't like 5er tailgates based on the way they look or the fact they let everyone see what your carrying in your truck bed. Not worth it IMO.

X2

I make the drive from Anchorage to Fbks all of the time. I tried a few with the tailgate down and some with it off. It never made any difference. I haven't tried any when towing a 5th whl trailer, but if it did save any fuel, I doubt if it would recoup your money unless you were driving a lot of miles like a commercial driver.

Consider the new tail gate to be like new rims - if you want it for the looks, then go for it, if not, save your money.

Bill

What of just removing the tailgate and replacing it with a soft mesh type? What does the average tailgate weigh? Would the reduced weight make any difference?

I've towed with and without the tailgate with both diesel and gas. Too many variables with wind to make an honest comparison but we've seen .5~~mpg better and it "felt" like it towed a little easier with the tailgate off. That's a LOT of wind being squeezed between the front of the 5th wheel and pickup bed to be trapped by the tailgate and bed sides.

Tests I've read show the following as compared to normal tailgate up.

Louvered tailgate while towing: Higher mpg
Louvered tailgate while not towing: Lower mpg

Normal tailgate down while not towing: Lower mpg

Bed cover while towing: Higher mpg
Bed cover while not towing: Higher mpg

However, the tests showed differences of only 1-3% mpg between scenarios.

Ask yourself how many gallons of fuel would that new tailgate would buy. Personally I don't like 5er tailgates based on the way they look or the fact they let everyone see what your carrying in your truck bed. Not worth it IMO.

I should have phrased the question differently. I am only referring to towing with the 5er attached. The tailgate would never be down in that situation, it would be gone or louvered. I am well aware of the insignificant differences when not towing, but there is a big ball of turbulence when I am towing, and I am looking for experience between the 2 with the same truck and the same 5er. That ball has to go somewhere when the gate is gone, so the question is where and to what effect. The truck is a 2WD quad cab long bed Dodge with a Jayco 345BHS 5er riding level.