New F150
 

Hello,
I recently bought a new f150 and started searching for cap, I came across this topic commercially-produced-aerodynamic-pickup-bed-cap-583 cant post links yet and spent the last two + hours all over this site. the 68 vehicle mods for better fuel economy ... is a really good read.

I'm looking for something to put on my bed that I can lock and protect things from the weather. So my question is, would a truck cap or a tonneau cover increase my mpg more ?

(Aero) Cap would be better if you can make it or get it.

All depends on the shape.
If it tapers from the top of the roof to the top of the tailgate, it will improve mpg
If it comes straight back from the roof, and then drops down 90 degrees at the tailgate (like a box shaped cap) it will hurt them
Tonneau has seen lots of mixed results on different trucks, but usually won't hurt much if at all.

I started with a regular flat tonneau, then after a while I mounted it on plywood triangles so it is angled back.
It isn't fully lockable, in that it could be cut, but it provides more theft resistance than an open bed, and keeps stuff clean and dry - and I can roll it up in about 15 seconds and have full use of the truck bed:
http://ecomodder.com/forum/showthrea...tml#post144148

Frank Lee is probably right as he has been here longer but my understanding was that a standard low profile cap would be about neutral for fuel economy gains/losses.

Most agree that a tonneau cover helps some and a properly designed aero-cap would be the best.


What kind of F-150 did you get? I just test drove some yesterday and am leaning towards a XLT supercab with the 5.0

Thats what I got, 2011

I was looking at a 100XQ. Straight back then curves at the tailgate.
Are you saying this will give me worse MPG then nothing at all?

Right now I don't have the time or tools to make an aerodynamic cap like what was done in commercially-produced-aerodynamic-pickup-bed-cap-583.html
I didnt read all 40+ pages, but didnt see anything about it being produced yet.

So unless a company makes an angled one with window and hinged door, my current options right now would been something like a leer (open to other company s if there's something better) or a tonneau.

yup, my understanding is that a regular truck cap (as opposed to an aero cap) will most likely hurt mileage, as it turns your truck into a big box, which is the worst possible aero shape.

The options for the truck bed, from best to worst for aerodynamics, are:
1Aerocap
2Tonneau (or half tonneau)
3Standard open bed (nothing added)
4Normal square truck cap
5Open bed with the tailgate down

I have never tested this theory myself, its just what I've heard - mainly around ecomodder, so try searching old threads to find answers from people more knowledgeable than myself.
All of this may vary depending on the vehicle, the load, and the mix of highway/city driving

Catching up on this late but I have a 2012 f 150 xlt supercap 2 wheel drive and the cab heigh cap I put on cut down my mileage a bit..1-2mpg..so if I was going for fuel economy I'd go for a lighter plastic tonneau cover I think.