Pickup tailgate up or down - SAE Studied

[bones33]

See this link if this iterests you. http://ecow.engr.wisc.edu/cgi-bin/ge...hi1/pickup.pdf

Results: Keep it up. Tonneaus MAY help.

[MetroMPG]

Great find! Thanks.

[palemelanesian]

If you look at the tables on page 8, the results are different for crew/extended cab than they are for regular cab / long bed. Ext cab - tailgate up, reg cab long bed - tailgate down.

[8307c4]

Originally Posted by PaleMelanesian

If you look at the tables on page 8, the results are different for crew/extended cab than they are for regular cab / long bed. Ext cab - tailgate up, reg cab long bed - tailgate down.

That was my experience as well, my '86 D-250 did get an improvement with the tailgate removed (std cab) but my '95 club cab did not.

Best I can recommend is do your own experiment, mythbusters is entertainment.

As for it up or down, I never understood this concept.
If up is the answer there is nothing more doing, have a nice day.
But if down is the answer then take it off and install an air mesh gate, saves another 20+ pounds of weight, why leave the stupid thing on?

[8307c4]

Originally Posted by PaleMelanesian

If you look at the tables on page 8, the results are different for crew/extended cab than they are for regular cab / long bed. Ext cab - tailgate up, reg cab long bed - tailgate down.

Agreed, my old 86 standard cab did see an improvement thou I will say I would rather remove the tailgate completely and install a mesh. But on my '95 club cab I am as well if not better off leaving the tailgate in place.

I would further bet it varies from one to the next, you just have to try it and see for yourself, but I do believe either way could work and there is no specific one-size-fits-all solution here.

[Snax]

This report confirms what I suggested in another thread, that there is a specific zone behind the cab after which it makes sense to attempt to establish more laminar flow off the rear of pickups. A longer bed, with far less impact from cab length, will benefit more greatly from aerodynamic aids for this reason. I would argue that if one had a bed length nearly equal to the height of the cab to the bed, it would not make any significant difference, tailgate, mesh, tonneau, or whatever because there is virtually no opportunity to re-establish a laminar flow that close to the cab at anything but the slowest of speeds where the impact is nearly nil.

In short, I think it could be argued that longer beds net better aerodynamic possibilities and shorter beds provide less opportunity for improvement. The length of the cab is relatively insignificant.

[ffvben]

I just watched part of the re-run of mythbusters on the pickup tailgates. you may loose .02 cd but if the 80+ lbs tailgate is removed wouldn't the mpg go up some if 100lbs = 1mpg. they didn't factor the weight reduction just focused on air disruption.

[8307c4]

Originally Posted by ffvben

I just watched part of the re-run of mythbusters on the pickup tailgates. you may loose .02 cd but if the 80+ lbs tailgate is removed wouldn't the mpg go up some if 100lbs = 1mpg. they didn't factor the weight reduction just focused on air disruption.

I noticed that too, but my truck weighs something like 3,700 pounds empty and the tailgate itself doesn't weight but maybe 50 to 70 maybe 80 pounds. It's not ueber light but I don't think it weighs 100, I can take it off pretty easily.

Then I have to remove at least 200 pounds to make a difference (400 is more like it), however on a club cab there's always the useless back seat (for some of us), and of course any of an amount of crap we like to carry with us might be best left at home, it can and does add up...

But in and of itself tailgate weight alone is not that substantial, however if you notice an improvement leaving it down then I would recommend removing it entirely and putting in place an air mesh.

[SVOboy]

I don't think that the weight reduction is worth nearly that much. Especially on something as heavy as a truck.

[trebuchet03]

I just watched part of the re-run of mythbusters on the pickup tailgates. you may loose .02 cd but if the 80+ lbs tailgate is removed wouldn't the mpg go up some if 100lbs = 1mpg. they didn't factor the weight reduction just focused on air disruption.

I thought they recorded empirical data with the tailgate removed... I'm fairly certain that factored in the weight reduction...

Originally Posted by SVOboy

I don't think that the weight reduction is worth nearly that much. Especially on something as heavy as a truck.

And even more especially at steady state -- not accelerating (unless the mass removed from the vehicle was spinning).