With gas prices as high as they’ve been lately, I really started thinking about how I could make my gas go further. Let me tell you how.
Zipping down I-71 the other day, it occurred to me that the back of my pickup truck was not aerodynamic. I could almost feel the wind dragging against me. So from then on, I’ve been pulling the hatch thing down and thus far, I THINK I’ve been saving gas. Also, I try to drive with the windows rolled up… I get the feeling that causes wind resistance too.
Now I don’t know too much about science, but I think this may be helping my gas mileage, but I can’t be sure… if gas IS being saved, it’s not overwhelmingly obvious.
So my question is threefold:
how much, if any gas am I saving?
will this only work at freeway speeds?
what is the name for the back part of a pickup truck that folds down?!
Yes. Maybe a mile or two per gallon, which for a 20 gallon gas tank can add up.
There still is some savings in city driving, but not as great as highway.
Tail gate, bed gate.
IIRC, in Virginia, its against the law to drive with the tailgate down. So check with your DMV on this. The most economical thing to do is buy a tonneau(sp?) cover which covers the entire top of the truck bed, or buy an airgate, which you may have noticed on some trucks (nylon webbing.)
Poor recollections here, but I’ll try to find some cites to back it up later.
In general, lowering your tailgate doesn’t do squat for gas mileage. The aerodynamics of the truck are already taken into consideration, so you actually get better gas mileage with the gate up than with the gate down. Don’t ask me the details, since my knowledge of fluid dynamics is minimal.
I believe a better approach to gas mileage would be a tonneau (sp?) cover, a flat, fairly hard fabric stretched across the open bed.
As for the tailgates, either take it off or put a mesh tailgate on if you want to go that route. I would hate to rear end a truck with the tailgate down.
I did some very unscientific experiments with my Tacoma pickup when I bought it last year and found that removing the tail gate did improve gas mileage somewhat… but only about 2-3%. I put on one of those plastic Gator nets across the back and noticed the engine wasn’t working as hard… especially at freeway speeds. Even a 3% reduction adds up if you drive enough (or gas is expensive enough).
I believe that rolling up the windows will also help a little since it makes the vehicle somewhat more aerodynamic… but I don’t have any cites for that either.
This is a second-hand cite, but I don’t have access to a Ford F-250 owners manual. I got this from a Truck Enthusiasts message board
Ah ha! I found a better cite. This is from Tom and Ray, the Car Guys:
There are dozens of places that sell tailgate nets or tell you to drop or remove the tailgate to improve gas mileage, but not one has any studies or statistics to support the claim. I’d go with the owners manual and the aerodynamics guys.
My guess as to why removing the tailgate seems to help gas mileage is that it’s about 50 lbs of dead weight. But lowering it should be worse, and I’m guessing that at highway speeds, having it up or a tonneau cover is best.
This is what I recall. Basically lowering the tailgate causes the ‘air stream’ to have to dip very low while having it up causes a more aerodynamic flow as the air in the bed more or less just stays there (it’s like you are hauling a load of air). Also a lowered tailgate increases rear end lift at speed giving less control and less breaking ability.
I recomend getting a tune-up and checking tire pressure (maybe go a little more then recommended)
Also the windows up will save gas. At highway speeds the windows up and a/c on will almost* certanally beet the windows open no a/c.
the one exception I have found was a 1980 Dodge Omni I had. It got about 30 mpg hwy and 15 w/ a/c hwy. The car got so cold that frost would form on the window and around the vents, some ice would come out of the vents but it never seemed to actually freaze up enough to block air flow. Now that was an a/c.
I haven’t noticed any frost, but when I turn on the A/C in my '95 Saturn, I can feel the car slow down. I haven’t felt anything similar when I put the windows down (although it might just be less sudden).
This is only at city speeds, though… more testing will be required for highway speeds.
That’s because the tiny little engine uses a signifigant portion of it’s power output to turn the A/C compressor!
But if you’re drag racing, put it down–it puts more weight farther back (pickups are very light over the rear wheels, and doing this improves the weight distribution a little), and helps the traction a tiny bit.
The Owner’s Manual for my Mazda pickup advises against driving with the tailgate down unless there is some kind of load on it (in which case they imply that it’s fine). Many of their advertising brochures depict the trucks carrying motorcycles, always with the tailgate down to allow the bike to fit. This page has such a photo.
The way you remove the tailgate from these beasts is:[list=A][li]Lower itLift it straight up[/list=A]Their theory is that a hard bump could cause the gate to come off of its hinges (which would really suck) unless some cargo was helping to hold it down.[/li]
I don’t have a cite, but I believe it’s quite legal to drive a pickup with the tailgate down in most places. In fact, it’s an advertised feature on many currently marketed crew-cab pickups (lower the tailgate and install the little cage they provide to get a free 2-foot bed extension), such as Ford’s Explorer Sport Trac and F-150 SuperCrew.
Not quite what you asked, but a person would save one hell of a lot more gas by changing their driving habits. I’d tend to leave areodynamics equations to race car designers or those breaking the sound barrier on land. Since a pick-up ain’t really designed for speed and low-drag to begin with, the best way to save fuel is to not waste it… drive slower, don’t use the breaks excessivly (fast-slow-fast-slow), drive smoother, etc. Yes, areodynamics do factor into mileage even for the pick-up, but you’ll be better off trying the above approach rather than fiddling with tail door positions and canvas; not to mention the reduced stress on the truck it’s self and a safer driving style.
I bought my pickup truck to save gas. I even got the miniscule 4-banger. Driving habits really DO have a lot to do with the pickup. Driving the speed limit to and from work (roughly 23 miles each way at 55mph), I can get close to 30MPG. However, driving how I drive, I get more like 19 (i.e., doing 85 until some idiot gets in the wrong [passing] lane). So, I usually drive the car, with a big engine, comfy, drive 80-90, and get about 25MPG. Interestingly enough, when I force myself to do the speed limit in the car, I get only about 2MPG difference, according to the car’s computer. My time is considerably more valuable than 2MPG.