Pickup tailgate up or down - SAE Studied

[kamesama980]

Originally Posted by VetteOwner

ye alike crosswinds, etc.

id like to test the tailgate theory but i have to have sandbags in the bed for winter traction...and yea they do slide around and 3 are up aginst the tailgate....so its a summer testing thing for me...

but if anyone has a 94-97 chevy s-10 (prolly best with the 4banger) that could test for me that would be great!

cut a 2x6 or 2x8 to fit across the bed in front of the fenders. as wide as the bed I mean. without wight it'll slide down to lay flat but set some sandbags there and viola. in front of the fenders it'll be forward i nthe eddy from the cab and it's low enough not to change much aero.

I have a 87 S10 4 banger. the 2nd gen weighs more and has a piddly excuse for an engine. it weighs about 2750lbs with me and gear in it so a little change is a lot of difference. soon as the cressida gas tank's empty I'll be driving the S10...I calculated 2300 miles to break even just on gas money. 25 city mpg and i can fit an engine, trans, tires, and tools and it won't bat an eyelash at hills. best spent $500 yet :-p

[VetteOwner]

Originally Posted by kamesama980

cut a 2x6 or 2x8 to fit across the bed in front of the fenders. as wide as the bed I mean. without wight it'll slide down to lay flat but set some sandbags there and viola. in front of the fenders it'll be forward i nthe eddy from the cab and it's low enough not to change much aero.

I have a 87 S10 4 banger. the 2nd gen weighs more and has a piddly excuse for an engine. it weighs about 2750lbs with me and gear in it so a little change is a lot of difference. soon as the cressida gas tank's empty I'll be driving the S10...I calculated 2300 miles to break even just on gas money. 25 city mpg and i can fit an engine, trans, tires, and tools and it won't bat an eyelash at hills. best spent $500 yet :-p

yea ive had the bags in front of the axel before and it accualy makes driving worse just weighs down the truck in whole so it slides more yet still spins the wheels like mad.

BUT ive taken the tailgate off and bags out. and taken the car when its snowy but now it snowed so theres like a foot of snow in the bed and thats plenty of weight

i dunno the 2.2L is slow (seems liek a rocket compared to a chevette) BUT its pretty torquey and can haul/tow a suprising ammount.

yea weight in S-10's dont seem to affect mpg that much they do affect acceleration tho

[8307c4]

I do recommend for a tonneau cover spend the $4-500 and get a good one.
I've done experimented with this and it's just a lot of hassle with the cheaper ones.

Mine only cost me about $60 but I spent a quick $20 or so on extra rope because the bungee system wasn't strong enough, then even the rope wasn't any good.

The riveted ones are just as bad for only slightly more, they run you 1-200...
Rivets break over time, every time that cover has to come off you risk breaking one.
Oh yeah, they also like to pop off at highway speeds.

But the biggest problem is aerodynamic down force, and rain!

At higher speeds (50+mph) there is a strong aero down force in the back, most cheaper covers bend under the load, and rather severely so. Then there's the rain, what a pita to wake up after a night of rain and have a cover sunk in full of rain water (hint: It's HEAVY).

I ended up installing a plexiglass sheet under mine, it helps keep it from bending as much but I just happened to have the sheet and even then it cost me another $20 in parts to keep it in place and another hour of my time.

So for the $100 economy cover I have now, I would've been better off saving that towards the 4-500 one, but live and learn, chalk one up to experience.

Get a real one, preferably hard cover but definitely not rivets, something more substantial and spring-loaded that lifts in one piece, something decent.

Originally Posted by theclencher

I believe "air meshes" have proven to have the worst aero of all.

Fair enough, but I have stuff in the bed heh

[GasSavers_Scott]

I also saw the Mythbusters episode where they made made hydro tunnel and said tail gate up was better, but I totally disagree. Back in the 80's I had a Ford Courier, it was a Mazda with Ford badges, an 1800 with a 4 speed. In stock form with the tail up I had to struggle to keep at 65 mph, I always had to keep my foot in it to do anything over 65 mph. The tail gate had 2 pins in it, I could pop the gate off in under a minute. So one day I did, got on the freeway and cruising at 65 was nothing, I could feel my foot farther back from its original buried position. Above 65 felt limitless, 75-80 no problem, mpg went from 28 to 31, I left it off unless I had to haul something.

Now with the bed cap issue, my bed fit a piece of plywood perfectly, it had about 10 hooks on the side, I'd spider web rope around all 4 corners and aerodynamically it acted the same as removing the gate. Mpg range was about 30.

So from my roadside laboratory its gates off or beds covered. Now an area that I don't even know if it will ever be looked at is the underside. Look at all the differentials, transfer cases, gas tanks, mufflers, and frame cross bars just hanging out there. Since trucks are so high to begin with, it seems their natural candidates for belly pans. I like the Bed Wedge of sloaping down from the cab back to improve truck aerodynamics. I think the biggest enemy that makes things like Hummers so unaerodynamic is flat square sides. Take the sander and round off all the edges on modern pick-ups and I think you'll start to see some better f/e.