Partial tonneau!?
 

I really wanted to cover my bed, but because of time and cost and designing it to work for everything I do (hauling firewood, plywood, drywall, etc.) I knew I wasn't going to get it done this year. Winter is approaching and I needed somewhere to put my sons pack and play, diaper bag and other things, and groceries. I was studying that chart that's floating around here comparing aerodynamic improvements for pickups and figured I could build a box to keep things in to act as my partial tonneau and then I just need to add a wing. The box is built and has been on for a full tank. I still need to cover it with bed liner and seal up some gaps. My mpg dropped a little for this tank, but I believe it was because I didn't control my foot as well as the last tank, and there was a day I warmed the engine up and lost about 0.3 mpg off my average at the time. Also the tank before this was my best tank ever, so not a really great comparison. When it's completely finished I might get around to doing actual tests with and without the box/tonneau (it just lifts out of the bed)

I'm considering a kammback/cab extension instead of the simple wing. So, question is how far back do I take the extension?

This chart in the attached pictures. and if your making a kammbach extension the longer you make it the more it will help.

Yeah, that's what I figured. I'm thinking about taking it back to the beginning of the wheel wells. It'll be about the same size as the box, and I'll have the middle section of the bed open for easy access. I think if I stack firewood up inside the extension I'll get nearly as much in the truck as I did using the full bed and stacking it just to the top of the bed. Of course I need to put something in to protect the back glass. I will have a board run across the bed at the cab. When I haul plywood the board and my box will make a "shelf" to lay it on, and I can just strap it down. Another advantage over a full bed cover is visibility (when I'm not hauling firewood anyway).

http://ecomodder.com/forum/showthrea...n-22142-7.html
http://i447.photobucket.com/albums/q...8-07163200.jpg

http://i447.photobucket.com/albums/q...8-17105613.jpg

http://i447.photobucket.com/albums/q...8-18131801.jpg

You can fold the top up and lock it there if you need more space...

You want the best possible mileage when you're hauling firewood because there is another energy conversion when the wood is burned, and the efficiency is affected.

The figure I saw in the seventies was anything over 60 miles and you're better off just burning the gasoline for heat.

And you get medical expenses from lifting the firewood over the side of the bed instead of to deck height. It would corner better though—less polar moment.

Sven,
I've seen the thread on that truck. It's nice work. I'd have to put a window in for rear view visibility.

Freebeard
As far as firewood costs go, I'm hauling wood I get for free and I'm guessing I spend around $10 - 12 round trip on gas to get it. Other than the trip I sat in traffic, I've not seen a huge affect on gas mileage from the weight of the firewood. I spent $2,000 one year heating with propane. I have burned wood ever since and I will never go back (unless I get to the point where I'm physically incapable of processing firewood myself and for some reason the cost of ready to burn wood becomes greater than other fuels). Even at lower efficiencies than propane, electric, etc. I save a lot of money.

As for the lifting I guess I'm silly enough that I usually lift it over the side of the bed instead of climbing up (not really a reach for me at 6'4" anyway). a full cover would be more difficult unless the entire thing hinged up, because my box slides out the back and then I can climb in and stack that way if needed. I can move the box by myself. When unloading however I do like to stand in the truck and throw/roll it out. Which brings me back to an aerocap that would have to lift up high enough for a 6'4" person to stand under.

I'll probably just mock something up and run the extension as far back as I can, at a slight angle until it starts to affect visibility and end it there. At this point whatever I do may have to wait until spring anyway.

My ultimate goal is a small single axle trailer with an aerocap to pull behind the truck. If I ever get the money together for that I will revisit the idea of a full aerocap on the truck.

Don't do that.

So you're saying burning fuel while sitting in one place and gaining nothing from it is bad?

Normally I wouldn't warm a vehicle but I had to get out of the truck because my dog was having trouble with his dog house in the middle of a storm and my son was already in the truck and needed to stay warm. I was already running late and my only other option was to take him inside put him in his bouncy chair, fix the dog house, run back before he cries too much, take him back to the truck and buckle him in his seat. So, yeah I broke my rule and did the illogical thing and left it running. I plan on adding a block heater when money allows but that's a future thread.

Being a broke a$$ single parent is fun.

I wouldn't say it was illogical, you were late. You should leave early according to the 100+ hypermiling tips. But having a child myself, I fully understand how running late can easily happen. In the end, you paid for the convenience of not baby juggling.

I can't believe you are 6'4" and can drive a ranger. I sat in a 93 today and I was comfy in the passenger seat, but don't know how well I would driving.