Does lowering the tailgate really help mileage?
11-28-2004, 11:12 AM
#1
Registered User
Thread Starter
Does lowering the tailgate really help mileage?
The title says it all-I've been doing all my driving with the tailgate closed. Will opening it actually help mileage on the interstate? If so, I might buy one of those metal things that replace the tailgate and let air through.
11-28-2004, 11:52 AM
#2
Registered User
Join Date: Aug 2002
Location: Northern Virginia
Posts: 8,803
Likes: 0
Received 0 Likes
on
0 Posts
According to genosgarage.com the DC engineers designed the Dodge Ram to be the most aerodynamic with the tailgate up. They say you may actually lose mileage by opening the gate. It's not on their site, but in their catalog....
11-28-2004, 12:28 PM
#3
DTR's 'Wrench thrower...' And he aims for the gusto...
Join Date: Oct 2003
Location: Smith Valley, NV (sometimes Redwood City, CA)
Posts: 2,668
Likes: 0
Received 3 Likes
on
2 Posts
To add a little to what Dodgezilla said, tailgate up has been shown to be better than down, or removed, or replaced with a net. And a bed cover is better yet. I think I saw that info in the latest TDR magazine.
Wetspirit
Wetspirit
11-28-2004, 02:38 PM
#6
Registered User
Join Date: Aug 2004
Location: Katy, TX
Posts: 146
Likes: 0
Received 0 Likes
on
0 Posts
Well I had to drive around for a while with no tailgate because someone stole mine and I did not notice a difference. If anything I agree with what these guys have said, it could hurt the milage
11-28-2004, 03:03 PM
#7
Registered User
Join Date: Nov 2004
Location: Bay Area, California
Posts: 155
Likes: 0
Received 0 Likes
on
0 Posts
My mileage went up 1.5mpg with the tail gate down, but this is a quad cab 4x4 dually, and it was with the computer calculation so who knows how off it is. I think tailwind plays a big part to, since the truck is so huge, it has to push alot of air out of its way to reach speed. Going to make a 275mile round trip next week and I'll see if tailgate down helps or hurts mileage hand calculated, not computer mpg.
Trending Topics
11-28-2004, 03:06 PM
#8
Chapter President
According to a study by Texas A&M a few years ago, the tail gate down did not difference. The test were done with smoke streams and verity of trucks with and without different air spoilers.
11-28-2004, 05:28 PM
#10
Registered User
I put about 500 miles on the truck over Thankgiving with the tailgate up...90% interstate and got 22mpg. Don't think you can get much better than that. I have a long bed.
Also, knowing the quality of the tailgate cables they put on our trucks, why would you want to drive around with your tailgate supported by those two rubber bands?
Also, knowing the quality of the tailgate cables they put on our trucks, why would you want to drive around with your tailgate supported by those two rubber bands?
11-28-2004, 06:27 PM
#13
Administrator / Scooter Bum
The difference between tailgate up and tailgate down was only in the 10ths of a MPG as I recall.
The Hard Tonneau cover showed a slight gain, as did a specially shaped bed cap.
The standard squared Bed cap hurt mileage again only in the 10ths of a MPG.
The net tailgates actually were reported as the worst for MPG as they don't allow the "bubble" of air to form in the bed and actually increased drag.
As for running the tailgate down, Have you ever seen a truck that was rear ended with the tailgate down?
The TG isn't designed to absorb a 5 MPG impact.
Takes out the gate and the bed.
Not a pretty sight.
Last thing to remember:
It's a TRUCK, and has the aerodynamics of a brick.
The Hard Tonneau cover showed a slight gain, as did a specially shaped bed cap.
The standard squared Bed cap hurt mileage again only in the 10ths of a MPG.
The net tailgates actually were reported as the worst for MPG as they don't allow the "bubble" of air to form in the bed and actually increased drag.
As for running the tailgate down, Have you ever seen a truck that was rear ended with the tailgate down?
The TG isn't designed to absorb a 5 MPG impact.
Takes out the gate and the bed.
Not a pretty sight.
Last thing to remember:
It's a TRUCK, and has the aerodynamics of a brick.
11-28-2004, 08:02 PM
#15
Registered User
Join Date: Sep 2004
Location: Brighton, CO.
Posts: 240
Likes: 0
Received 0 Likes
on
0 Posts
Car and Driver recently did a stint on truck mileage with tailgate up vs. tailgate down. They generated a computer model of a Ford F150 extra cab (or whatever they call it) and ran the model in a CFD (Computational Fluid Dynamics) program. They varied a few parameters but the result was always LESS overall drag with the tailgate UP! The reason is with the tailgate up, the Eddie currents in the bed were smaller and more localized than with the tailgate down. The Eddie currents I'm referring to are the circulating air currents in the bed behind the cab.
They also did tests with a simulated tonneau cover, the CD numbers (CD = Coefficient of Drag) were significantly lower (i.e. less drag = better mileage). Their suggestion was to leave the tailgate up, and if you can get a tonneau cover for the bed.
If I find some time I’ll look up the article and post the month and issue No.
Leave those tailgates UP!
They also did tests with a simulated tonneau cover, the CD numbers (CD = Coefficient of Drag) were significantly lower (i.e. less drag = better mileage). Their suggestion was to leave the tailgate up, and if you can get a tonneau cover for the bed.
If I find some time I’ll look up the article and post the month and issue No.
Leave those tailgates UP!