Do not put tailgate down to save gas...

amoraamora Member Posts: 204
edited April 2014 in Toyota
I ve seen many pick-up trucks on freeway with
tail gate down. THIS IS NOT GOOD, CAN WEAKEN
HINGES, also there is no MPG improvement, you
aeronautical and engineering buffs would know
this. A Vortex is created at rear of cab,
trapping the air.

A toneau cover will do the trick.

TO ALL TAILGATERS: Stop using your tailgates to
save gas. If you claim you are getting better
MPG, recheck your math.....


  • eharri3eharri3 Member Posts: 640
    It may also be unsafe if the thing slides off in traffic. If you want to experiment and find out for yourself, take the it off completely... on most newer trucks its easy, requires no tools
  • kit1404kit1404 Member Posts: 124
    I haven't seen anyone driving with the tailgate down in years. And, actually those net-things aren't so popular either anymore. Have you ever watched a full-size truck on a really bad, rough road without the tailgate - the fenders start to vibrate some. The truck needs the support of the tailgate for the bed to be properly supported, unless you got a heavy load and/or a big camper in the back and that seems to settle things down. Just don't do it. Think about body on frame construction, springs designed to bounce without a good load and the other things that support other things. It won't help anyway with your mpg. Plus, you could lose your tailgate if you leave it down - that part seems to depend on the manufacturer's design. I see signs on my road with people looking for tailgates that fell off for whatever reason!
  • obyoneobyone Member Posts: 7,841
    with no tailgates at all. And with people sitting in the bed....nuts.
  • modvptnlmodvptnl Member Posts: 1,352
    You're totally WRONG!!.......................

    Just kidding.LOL!!!!
  • amoraamora Member Posts: 204
    Live in So. Calif, drive 78 mi one way to work,
    car pool also. See thousands of cars, trucks
    everyday. See many many trucks with tail gates
    down, mini, full size, in fact saw a F250HD
    reg cab long bed with tail gate down.....INHO if
    (another topic) people want a true economy car then BUY A 1969 CHEVY NOVA WITH IN-LINE 6 from
    wrecking yard, offer $200.00, then rebuit motor for under $300 if you can and you should get
    16 mpg for 10 years. THIS IS TRUE ECONOMY CAR,
    twenty thousand big ones buys lots of gasolene....
  • amoraamora Member Posts: 204
    roads in windy conditions with tailgate down.
    In So. Ca we have SANTA ANA WINDS that you can feel while driving no matter if driving a HUMMER or YUGO SS...
  • amoraamora Member Posts: 204
    Long live the DOHC Yamaha alum heads on Vulcan
    cast iron FOMOCO 60 degree block, LOL....
  • rrichf1rrichf1 Member Posts: 47
    Be thankful that they're riding in the bed of the truck. They're just preserving the gene pool for the rest of us.
  • markbuckmarkbuck Member Posts: 1,021
    My old CC F350 diesel used to get it's best fuel economy during river trips where I had the bed full of rafts and junk, a bunch of canoe's and kyacks on the roof, and running about 60 mph. Figure the boats on the roof really helped streamline the air over the bed or something plus a full bed plus slow speeds.....
  • mledtjemledtje Member Posts: 1,123
    If you want to improve fuel economy on a PU, add a shell or a tonneau cover.

    It always cracks me up to see trucks with the tailgate down, usually it is a truck with a 6-10" lift and 35"+ tires and suddenly he wants better mileage??

    Mike L
  • oldharryoldharry Member Posts: 413
    I found that I save a little fuel if I move the seat back an extra notch. Makes me think about it when pressing on the accelerator. :<)

  • erikheikererikheiker Member Posts: 230
    I'm 6' 2" and I already have the seat back all the way with the headrest touching the rear glass. Guess I'll have to buy an extended cab and move the entire mounting system back. But that will make for a tight squeeze in the back! But I'll save a bit of gas!
  • rrichf1rrichf1 Member Posts: 47
    Somebody once posted a link to a term paper project on wind resistance and pickup trucks. The students used a Dodge and showed some rather graphic evidence of the air flow over the truck. It seems that the lowest coefficient of drag was obtained with a shell with round corners. I don't have the url but if anyone has the link it is really worth looking at the results of the experiments.
  • amoraamora Member Posts: 204
    DODGE RAM pickups with the RAM head emblem protruding on hood; "PULL TO SIDE OF ROAD, STOP,
    FACING THE WINDSHIELD" the wind resistance should be somewhat less to the tune of an increase in
    fuel mileage by about .0003 %
  • oldharryoldharry Member Posts: 413
    maybe if you just took off your right shoe. . . :<)

  • mdecampsmdecamps Member Posts: 115
    I have a '98 S-10 and do a lot of highway traveling. I gain 3mpg with the tailgate down. You can say what you want, but I have tested this theory time and time again. It's never "fell off" in traffic, either!
  • amoraamora Member Posts: 204
    Have owned 4 S10s, '87 4X4 ext cab 2.8L, 88 S10 4.3, '91 S10 4X4 4-DR
    Blazer TAHOE 4.3, '00 S10 reg cab XTREME 2.2L.....fuel tank gauges
    are very erratic in these vehicles and therefore a true accurate
    calculation is difficult, approximations are ord of the day....
  • timothyadavistimothyadavis Member Posts: 322
    nobody uses the fuel guage to calculate mileage, do they? For the obvious reason that you state, you cannot tell how many gallons you have used by the guage. You can tell though, by refilling the tank all the way and the same way each time -- preferably at exactly the same station and pump so that the vehicle is sitting at the same angle each time and so that the cut off tendancies of the specific pump/nozzle don't vary. Of course, then you use the mileage by either the trip odometer (which you immediately reset after recording the mileage so you can do it again) or, if suspicious of that reading, the regular odometer reading and subtracting from the previous reading. If this sounds painfully obvious, I apologize, but your post seemed to indicate that you didn't think of this method....
  • amoraamora Member Posts: 204
    Apology not required, I am the one that is sorry I did clarify my
    statement. I have filled the S10 gas tank to the spill level and
    have run mileage checks based on odometer readings and the
    amount of fuel at each fill up (spill level). I have received
    various non consistant readings also including tail gate in down
    position. If I average out all readings they are same with tail gate
    down or up. I have run 500+ mile checks from Los Angeles to San
    Francisco on the infamous Grapevine and highway 5.... the variance
    has always been +/- 2-3 mpg....I also used my HP32SII RPN SCIENTIFIC
    calculator...(mult, divide and enter keys) also pencil and small
    notebook for manual calcs....
  • timothyadavistimothyadavis Member Posts: 322
    I see.... ;-)
  • drowe1drowe1 Member Posts: 5
    At the speeds I drive 80+ usually I always get better mileage. PLUS it is WAY more stable. When the tailgate is up you can feel the bed load up with pressure from the air coming over the cab into the bed. Then when the air pressure gets high enough the air coming over the top just continues over the bed stripping the air away with it leaving a lower pressure area and WUMP! you can feel it hit the bed again. Unsettling! Naturally a cap would be even better but I do not like the look.

    94 Ford Ranger ext cab 2wd
  • quadcab4x4quadcab4x4 Member Posts: 44
    Tailgate up-down makes little or no diff. Have tried both ways. Did all the math. The person with the pen and paper, I forget who- did you have a head wind,tail wind? Now that would make a diff.
    A cap might make up 1 mpg. But due to it's extra weight that might X out any increase in mpg..

    I have heard that if you put your arm out the window, that right there is 3 mpg loss...

  • kit1404kit1404 Member Posts: 124
    None of the above is likely to make enough difference in gas mileage to be worth consideration.
  • greg116greg116 Member Posts: 116
    You all have valid arguments when it comes to aerodynamics and such, but I've seen little discussion about simple tonneau covers! Wouldnt that provide the "gain" in economy without the wear and tear on your hinges and straps, or added weight (and price!) of a cap? Okay, they reduce cargo capacity, but most people dont have anything in their beds most of the time anyways, right? You could get a lightweight snap-on cloth/plastic thing that comes off in seconds.
  • greg116greg116 Member Posts: 116
    ...But if you put out your hand so the palm is facing twoards the road, and then tilt your fingers up, wouldnt that deflect air and make the vehicle lighter? j/k
  • superjim2000superjim2000 Member Posts: 314
    Plus some covers roll up when you need to haul stuff.
  • greg116greg116 Member Posts: 116
    My father bought a '98 Durango 4x4 SLT 5.9 and (I think) 3.92 rear end. After the break-in, it saw extensive highway driving. After seeing the damage caused by all these highway miles, he put on a bug deflector. Not only did it dramatically reduce stone damage, but from what I can tell, gave us another 3MPG! I drove it on a 14-hour two-day trip over the Rocky Mountains and averaged 18.5 MPG. Okay, it was pretty well empty, and just me driving with a light foot taking my time, but I don't think easy driving can account for 3 whole MPG by itself...
  • obyoneobyone Member Posts: 7,841
    which leads to the methodology used to calculate the mpg. How was it done?
  • greg116greg116 Member Posts: 116
    Trip computer. True, they're not the most accurate things in the world, but it's been pretty consistent so far.
  • brianinvegasbrianinvegas Member Posts: 53
    Many months ago I saw a post from some guys with access to a government wind tunnel and tested the coefficient of drag on their new Silverado with tailgate up and down. The tailgate up actually had a very small advantage but too small to make a difference. I remeber it because it seemed so odd but can not remember who posted the results.

    I have a hard tonneau cover on my '00 Z71 ext cab and noticed a small improvement (.5 mpg) but then Vegas changed to that oxygenated gas and everything went to heck.
  • quadcab4x4quadcab4x4 Member Posts: 44
    I've never done the math on a tonneau cover. In theory it sounds good at least better than the tailgate one. I don't think it would hurt..

    I know you said it was a theory "greg116" about a bug shield improving mpg. That was pretty funny, 3mpg wow! I think that it would most likely block the wind don't you think?? If I could get 13mpg as opposed to 10mpg I'd buy one tomorrow.

  • greg116greg116 Member Posts: 116
    I know about all the risks associated with leaving the tailgate down, hinges wear etc... but arent modern trucks designed to accept that? Example, Ford Explorer Sport Trac and Dakota Quad Cab etc... have those flip-out cages that extend length with the gate down, encouraging tail-down driving. What are youre thoughts on that?
  • steve234steve234 Member Posts: 460
    Those bed extenders are for short term use only. They also provide a small degree of support for the sides.
  • kit1404kit1404 Member Posts: 124
    Slow down - makes my old F-250 4X4 with 460 gain about 10% just adjusting my driving from 78 mph to 75 mph - the speed limit in New Mexico. With my 1999 F-150 4X4 with 5.4 I have noticed similar savings on mpg - granted I only slow this dude down from 84 to 81 mph - but it does make a difference. For me, shells and bug deflectors have never made a difference that I could see and I check my mpg everytime I fill up on both trucks. Let's face it - even the most improved aero designs are still pushing a lot of weight thru the air. The speed matters more than anything else.
  • greg116greg116 Member Posts: 116
    Losing an average of 10 kph over a two-day trip gave me 18.4 MPG as opposed to 17.5. Speed kills gas!
  • mkstringmkstring Member Posts: 53
    A light foot driving can increase MPG dramatically. And by 3 or 4 MPG per tank. I have a 92 Toyota excab 4x2, 5 speed, v6. On the tanks that I purposefully drive with light acceleration, I get 21-22 mph. In the tanks that I accelerate heavy (normally), I get 17-18. Tailgate up WITH a bug deflector the whole time.

    I completely agree with you and kit1404 about slowing down. Texas is at a 70mph limit, and there's talk about taking it back down to 55 to help with the smog problem (even though vehicles are the smaller of contributors to pollution in the Houston area. I'm all for it. Too many people around driving 85 and thinking the highways are a racing contest.
  • toddstocktoddstock Member Posts: 268
    I am thinking of getting a tonneau cover... What are we talking here, maybe 1mpg better or is it less...Not sure...
  • lariat1lariat1 Member Posts: 461
    You probably will not even notice a difference unless you have an 8' bed. With a 6.5' bed the air flows over the tailgate for the most part but with the 8' bed the air comes off the top of the cab and hits the tailgate.I have a tonneau cover on my 6.5' bed and I never saw a change in MPG.
  • gmarkhamgmarkham Member Posts: 28
    For all you aspiring Chevy Silverado Owners. If Chevy ever gets its act together regarding the Pro Tec Composite Box that was suppose to be available on 2001 models (optional item), the fifty pound weight reduction (short bed version) could reduce gas mileage and would only cost you $800.00. You would also not have to purchase a bedliner. Lets all hope Chevy has these Pro Tec Box's for 2002, because thats when i'm going to replace mine. Who knows maybe there will be a composite box message board someday.
  • rea98drea98d Member Posts: 982
    A plastic pickup bed? Definately not for those who only need a truck for the things a truck is good for. The way my grandfather worked his 84 Chevy Silverado, he would have crushed that bed to pieces in no time. It might be perfect for a Silverado SS answer to the Ford Lightning, but as far as being an actual working truck, don't hold your breath.
  • gmarkhamgmarkham Member Posts: 28
    In response to rea98d, according to Chevys Truck 2001 catalog, They show a bulldozer dumping rocks in the truck bed. They also illustrate a hammer being swung into tailgate with no ill effect. Composite material is not the same thing as plastic. I am not defending CM nor has this truck bed made it off the assembly line. In fact I have never even seen one except as illustrated in Chevys catalog. If this truck box is as tough as they say (and even side walls wont dent) and on top of that is 50lbs lighter and eliminates the need for a bed liner then I'm sold and sticking with the subject of this message board will give you better gas mileage because of weight reduction. Anybody out there hear about what the future holds for the Pro Etc Composite Box please chime in.
  • sporttrac4x4sporttrac4x4 Member Posts: 13
    I own a Ford Sport Trac with composite bed it is tested with far more demanding tests than any steel bed could withstand. Composite is lighter and stronger than steel dosnt rust and needs no bedliner. The same plant that makes the beds for the Sport Trac will make beds for Chevy Avalanche and others,

    Ps rea98d you really should read up on subject before inserting foot in mouth.
  • sporttrac4x4sporttrac4x4 Member Posts: 13
    If anyone is interested in more detail email me at [email protected] and i will get you the link to the factory that builds the composite beds. They have an excellent write up on the process used to make them and the tests that Ford requires of them. They now make beds for Fords Sport Trac and i know they have the contract for the Chevy Avalanche. The factory is in Baltimore and independent of any auto manufacturer.
  • michgndrmichgndr Member Posts: 160
    Airplanes with metal wings...7-9 Gs. Airplanes with composite wings...more Gs than a human can stand. Tough stuff.

    Think about it.
  • rea98drea98d Member Posts: 982
    Sorry guys, but I've heard promises about composites before, only to see things made with them fall apart in a few years. Save the marketing hype, I wan't to see these truckes in the real world getting the snot kicked out of them by masses of buyers before I'm convinced.
    As far as airplane wings go, those airplane wings cost a whol lot more than anyone would ever want to spend on a truck. And most of the metal-winged airplanes in our Air Force can black the pilots out and be nowhere near the plane's limits.
    Sporttrac, I'm gonna send you an e-mail. I'd like to read that link.
  • sporttrac4x4sporttrac4x4 Member Posts: 13
    SMC components for the Ford Explorer Sport Trac are also manufactured by the Budd Plastics Division, at its North Baltimore molding facility. Budd recently expanded the 250,000-square-foot plant with an additional 100,000 square feet of manufacturing space, largely due to contracts for the new Ford and Silverado truck parts, relates Mike Dorney, Plastics Division vice president of sales and marketing. The company molds the Sport Trac's single-piece cargo box inner panel of structural grade vinyl tester SMC (50% glass by weight) in a 2,500-ton press. Budd also molds the box outer panels or fenders for the Sport Trac of 27% glass-reinforced SMC. Both the right- and left-side fenders are molded together in a 2,000-ton press. In addition, Budd molds the unique foldable hard tonneau cover of 27% glass-filled SMC. The formulation for the Sport Trac
    cargo box was set at 50% by weight to meet Ford's durability requirements. Budd produces its own SMC material at the Plastics Division's Van Wert, Ohio compounding plant, using fiberglass from Owens Corning and resins from Alpha Owens Corning (East Collierville, Tenn.) and Union Carbide Corp. (Danbury, Conn.). On the Budd production line, few operators are involved in molding the cargo box. Two operators at the front of the press pull the SMC material off the roll, lay it on a table where an automatic slitter cuts it to length, and place it on an automated loader. Two plies of SMC material, cut in the same rectangular shape and size are used for each cargo box. The loader positions each sheet on the mold before the press closes. An automated picker pulls the finished part out of the mold and places it in a cooling nest, where it remains through a three-stage cooling period. Another operator deflashes the box with a sander before it moves on to other secondary finishing stations, some of which are automated. Bill Mellian, Owens Corning's Ford North American business manager, says he is very impressed by the high level of automation that Budd Plastics Division has attained in the production of the cargo box. Minimal handling leads to better part consistency and higher throughput," he says. "The automated charge loading and placement are very critical in terms of producing the right flow pattern and glass orientation. That and the rest of the automation speaks highly of Budd and the progress the industry has made." Secondary operations include drilling holes in the cargo box,
    including four in the bed for the attachment of the box to the truck's frame with bolts. A steel D-pillar assembly is bolted to the rear of the box to reinforce the tailgate opening, enabling it
    to remain square and upright through repeated slamming of the tailgate, explains Dorney. The box is painted a flat black with a finish designed to replicate the look of plastic bedliners. It is
    baked in a 300-degree F. oven before shipping to Ford's Truck Assembly Plant in Louisville. At the plant, the box is lowered onto the frame and attached at the end of the trim assembly line.
    Conversely, the SMC fenders are attached in the plant's body shop at the front of the assembly process and go through the normal paint system. The Sport Trac's tonneau cover is assembled by Budd from four molded panels, two outers and two inners. Molded two-up on the press, the panels are bonded together to form two halves of the cover, then painted flat black, and assembled into the final product. That includes attaching a long piano hinge
    that joins the halves in the middle, adding seals around the periphery, locks, handles, an inside safety cable release, and bungy cords to hold the cover partially opened if desired, notes
    Dorney. Warranted by Ford, the tonneau cover was designed to endure the OEM's same durability testing that the rest of the vehicle had to go through, he adds. Ford engineers put the
    equivalent of 450,000 miles of durability testing on the Sport Trac's composite cargo area, the company says. Some of the same tests if performed on steel pickup beds would cause severe damage. That did not occur on the composite bed, Ford adds. "Not only is the inside durable as can be, but the inner and outer panels of the cargo area won't dent and won't rust," comments David Paul, Ford systems engineer for the composite area. "If someone heaves their bike into the cargo box, it will not damage the inside of the box like a painted steel box," he adds. All of the required Ford tests were run on the composite box, including dropping a 55-gallon drum on it and extreme temperature testing. In addition "typical customer tests" were conducted such as dragging cinderblocks across the floor and throwing in steel pipes and 35-lb. angle irons and stirring them around in the cargo area, Ford says.
  • rea98drea98d Member Posts: 982
    If all of that Ford says it did is true, I'm impressed. (Ford has a habit of building wonderful prototypes, and then cutting too many corners when it comes to rpoduction.) I'd still like to see some real world durability before I'm sold, though.

    FWIW, I don't think the sport-trac will be seriously considered by people needing a work truck. Is Ford planning on making an 8-ft F-150 version of this thing?
  • sporttrac4x4sporttrac4x4 Member Posts: 13
    Ford does not manufacture the bed Budd Plastics does and they also have orders from Chevy. The article was also written from Budds view not Fords.
  • mledtjemledtje Member Posts: 1,123
    Both Ford and GM are introducing the composite bed in small steps. They know a lot of customers are skeptical - like rea98d, and the big companies have been burned by new ideas before!

    So, they are introducing the beds in relatively low volume, light duty applications. By the time the bring out full size beds in composite they will have many years of actual use to rely on.

    Mike L
  • rea98drea98d Member Posts: 982
    If real-world use proves its as durable as Budd claims, I guess I'll have to concede that they did something right for once. Anyway, it's good to know that this time, they're taking their time and doing it right.
This discussion has been closed.