Bakatare
10-19-2006, 02:39 PM
Does it really help any :confuzeld ?
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fauxpas 10-19-2006, 02:50 PM From what I have read...no. The trucks are designed for the best fuel mileage with the gate up. That would only make sense. Mythbusters (FWIW) even checked it out... "Driving with the tailgate down actually increased drag on the pick-up and caused it to consume fuel faster than the identical truck driven with the tailgate up. It was later revealed that the closed tailgate creates a locked vortex flow that created a smoother flow of air over the truck. With the tailgate down the trapped vortex was dissipated and the drag increased." DJFriar 10-19-2006, 02:55 PM x2 on what fauxpass said, the tailgate down acts a wing and increases drag. sixxgunscott 10-19-2006, 06:26 PM :exactly: Unit453 10-19-2006, 06:43 PM I dont possibly see how but I guess I'll buy it. SCQTT 10-19-2006, 06:51 PM Air bubble inside bed with tailgate up. Really, no chit Puffer 10-19-2006, 07:05 PM Plus tailgate gets chipped up bad running with it down. towdog333 10-19-2006, 07:12 PM Plus tailgate gets chipped up bad running with it down. Plus it looks stupid:D bristolbroke 10-19-2006, 08:38 PM Mythbusters had an episode on this and they ran the truck through several tests and it got better gas milage with the tailgate up. Not sure why something to do with drag. Sure you could find the episode somewhere if you tried.... 06bowtie_guy 10-19-2006, 10:00 PM Plus tailgate gets chipped up bad running with it down. :exactly: Had to drive my other truck with the gate down on a 4 hour drive. Longer load than 8 feet. Did a good number on the gate. ChrisHin 10-19-2006, 11:38 PM I saw that Mythbusters too and I guess it is true that its better to have your tailgate up. With the tailgate up it creates a air bubble that helps the wind blow over your bed and creates less drag. Ruben Z 10-20-2006, 12:52 AM Because with tailgate down, the air moves over the cab and pounds down on the bed putting more downward force on the truck bed. WIth the tailgate up you create sort of a bubble and the air doesnt really come into the bed. Just drive you truck fast when its raining and you will notice what ever is in the bed doesnt really get that wet. Thats because the wind flow never really comes down into the bed. ob_1jr 10-20-2006, 01:49 AM Also, if you ever get rear ended with it down....you have to watch that it doesn't come through the back window. if anything take it off, but as everyone says about mythbusters is true. sierradiesel 10-20-2006, 07:58 AM Doesn't make any difference in my truck at highway speeds of 65+. I usually do it to clean out the bed. DieselDuner 10-20-2006, 10:44 AM Doesn't make any difference in my truck at highway speeds of 65+. I usually do it to clean out the bed. acutually, that is how the tests were completed and it made a differance of like 35 miles or so.............. double d 1 10-20-2006, 09:31 PM im not dissputing what anyone has said but what truck did they test? are all trucks the same? reg cab, extended cab, or cc. and the differant manufactures? DJFriar 10-20-2006, 09:35 PM im not dissputing what anyone has said but what truck did they test? are all trucks the same? reg cab, extended cab, or cc. and the differant manufactures? It wouldn't change much, if anything the large the cab, the more the airflow would move over the bed. But its a fairly basic airflow model. The manufacture and configuration of the truck really wouldn't affect it enough to change the fact that the tailgate down is worse. Towsaboat 10-21-2006, 02:42 AM I have also read that the tailgate provides a bit of reinforcement for the sides of the bed, much like a full roof makes a car stiffer than a convertible. Don't know how a cover affects the airflow bubble, but the marketing push is it can help mileage. Haven't seen an increase in mileage with mine, but loving my Retrax cover. Had 1200 Lbs of Compost in the bed and it stayed with me instead of all over the road on the way home with the cover closed. Truck rode much smoother too with that load. mrfixit 10-21-2006, 11:10 AM If you like the paint on your tailgate I wouldn't recommend driving with it down. Just take a look at someone's gate that does it regularly and you will see what I mean. :badidea: Oh and I don't think that a cover really changes fuel milage noticiably + or -. Diesel_Dog 10-21-2006, 11:34 AM Not the throw a wrench into this thread or anything, but what about with the tailgate completely off? Would the weight savings improve the MPG over the 'air Bubble'? Anyone figured out how much weight(on the truck) they would have to lose to get better MPG? Ruben Z 10-21-2006, 11:41 AM The bottom line is all car manufacturers put a scaled model in a wind tunnel to see air fow and aerodynamics and how it affects the cars driving ability. By remove the tailgate you are altering the overall wind flow and making it worse. txguppy 10-21-2006, 02:43 PM Right on Bobcat.^^ There's even a University study posted on the net that substantiates this. The only thing to show a slight mpg gain was a toneau cover. snonut12 10-22-2006, 11:47 AM Put some leaves in the bed and you'll see how the leaves will circulate around the bed and not be blown away. That is the air bubble which cause the wind to flow over it and cause less drag. Of course the leaves will eventually get blown away, but not so quickly. Joey D 10-22-2006, 12:22 PM To add to this look at the cap on the 1500 tailgates, it has a small lip to help the air the comes from under the truck and up the back of the tailgate roll with the air coming over the tailgate. It's only on the trucks that have to meet milage standards like the 1500's. toytech 10-22-2006, 01:00 PM I read an article years ago in Popular Science about this. They checked air flow in a wind tunnel with tailgate up, down, and off. The results were tailgate up less resistance. elvis_knows 10-22-2006, 01:10 PM http://dieselplace.com/forum/showpost.php?p=1349739&postcount=21 | ||