Ohhhh that's great!

 

I asked this same question of my Physics teaccher from high school back in 1997! We spent an hour and a half one day after school going over some formulas to determine which way was the best for fuel economy. We concluded that while it wasn't a huge difference, it was better to just keep the gate up. Less work and you don't have to worry about pulling a BigBlue Which I too have done

 

I've read all the studies on the tailgate senerio. But my ? is. How about when your towing a 5vr? Tailgate up or off completly? I don't have 5vr tailgate yet for this truck. The one I had on the 01 wouldn't fit the 05. Seems to me once the air hits the 5vr some of it would go up & over, but some might get pushed back to the tailgate & add to the wind drag. What do you all think?

 

Slighty off topic, but has anyone come across a reputable test of with and without a hard tonneau cover in place?

 

I believe I read in that study on the tailgate they mentioned that the tonneau would be a help against wind drag.

 

Trucks with toppers get the best fuel milage as it makes the air flow more uniform. 5th wheel tailgates work yes depending on the design of the trailer and the distance from the down flow of air to the front of the trailer, I put a deck on the truck and it changes the flow pattern completely.PK

 

i would say the weight and drag from the 5vr negates any negative effects from the tailgate being there or not...just intuition, no facts. sorry

 

A long time ago, someone (from the TDR) found this study. It used a scale model of a Dodge Ram standard cab long bed with no outside mirrors as the baseline.

Variations to this baseline were made and studied in a water chamber. I copied the info and attached it to a .ppt document. I didn't get to finish the document, so it may be redundant on some pages. I'm attaching it, sorry if you don't have .ppt. [I thought I could attach it, but I guess not. Anybody know how I can make this .ppt available?)

The study was done at Western New England College, using engineering to solve real-world problems.



Here is the results, in case you don't have .ppt:

New Cap Design - Cd = 0.302 - 30% Decrease in drag

Tonneau Cover - Cd = 0.381 - 11.81% Decrease in drag

Lowered Tailgate - Cd = 0.414 - 4.17% Decrease in drag

Baseline condition - Cd = 0.432 - (tailgate up)

Removed Tailgate - Cd = 0.447 - 3.47% Increase in drag

Replace tailgate
with a cargo net - Cd = 0.461 - 6.71% Increase in drag

Square Cap - Cd = 0.480 - 11.11% Increase in drag


- JyRO

 

The test the Mythbusters did had absolutely no scientific validity.

First off, how the heck do they know that both trucks get the exact same mileage when driven exactly the same? It always seems that two vehicles of the same model never get the same mileage.

Second, they drove on the open road in traffic. There is no way they could have used cruise control to accelerate all the time plus I'm sure the two of them didn't brake exactly the same.

A real test would have been to do this at a race track or other closed course. The first test would have been with both vehicles in the same condition to verify that they get the same mileage. The second test would have them drive around the track or course with cruise so they never had to brake or accelerate.

The margin in mileage was so little that this test is at best inconclusive. The same test run again in the same matter may have shown the tailgate down to be equal to tailgate up.

Mythbusters is a TV show and none of the tests they do are really science. It is entertainment. I am suprised someone hasn't been seriously hurt yet. The testing of a rocket motor indoors was just plain stupid!

Brian Elfert

 

You mean Kari?
http://dsc.discovery.com/fansites/my...t/meet_03.html

 

You ain't kidding! I was shocked they would even show that on TV. They're (and this isn't ment to be too melodramatic) kind of dragging science's good name through the mud. Is blowing up a shipping container indoors fun? You betcha. Is it science? Hell no.

"Kids - don't try this ... EVER! These guys are morons!"

 

the first thing i do when i get a new truck is throw the tailgate off into the bushes i tow 90percent of the time and so its so much easyer with the gate off and my beds are rhino lined and i have never had a problem with any thing sliding around at at once in a blue moon i do have to use the tail gate if iam loading the bed with all my camping gear.

 

I tried to watch but ZZZZZZZZ... I was wondering how that ended.

 

I don't know about where most of you folks live, but I believe here in Washington, it is illegal to drive a p/u on the roads without a tailgate of some sort on the truck and in the up position.

DMH

 

Those mythbuster guys really bother me. I also think it is more entertainment than science. And, it's boring the way they present it. They are not focused enought. They are trying to be entertaining more so than teaching us someting.

I have a "flow through" tailgate. Bought it becasue it was a cheap replacement. I didn't really notice any effect on mileage. Anyone else??