Truck undersides smoothing idea

[Blu3Z3rg]

Originally Posted by darcane

This image gets posted somewhat regularly on here:


GMC Truck Division found three areas to tweak that netted a combined 2+mpg increase. So, I think filling this void is certainly a worthwhile endeavor.

I used corrugated plastic on a frame made of steel strapping (see thread in sig). I planned on covering the voids on the frame rails with the same construction, I just haven't gotten to it yet.

Absolutely the picture I was thinking of.
I have a chin spoiler, I have a hard tonnau cover, and now I'm hopeing to redo the exhaust, and, while i'm under there, cover the side areas highlighted.

[Blu3Z3rg]

Originally Posted by t vago

You could make an aerocap out of that foam. I wouldn't place it on the underside of your truck, because of its flammability and nearness to the exhaust.

Will be redoing the exhaust at the same time on a lift. Really, if people think that Coroplast is non flammable and THAT's ok under there, then you're sadly mistaken. Now, if you do your research, it's probably MUCH less flammable than most other things, but the foam I'm refering to is actually a part flame retardant for building structures between block and bricks that we use on our construction sites. This is NOT your normal foam, it's slightly different, and it's actually 1 1/2" so it may not be ideal anyways.

I will probably wait until I get to a job where they are tearing out some ductwork or something to get the sheetmetal and use that perhaps.
I don't really have a cheap coroplast supply around here.