[HydroJim]

I applaud your effort, but there are some things that can be improved.

1: From the pictures, it looks as though you're adding a significant amount of frontal area to the truck which negates your aerodynamic benefits. Simply lowering the height of the aero cap where it transitions to the truck cab would improve the aerodynamics.

2. It also appears the angle of your cap is too steep. By following the streamlining template, flow could probably be significantly improved.

3. The corners are square. rounded corners will prevent a fuel robbing vortex from forming and help to improve your design.

4. You could definitely cut down on the weight. The biggest potential I see is all the steel that goes around the top of the truck bed. It doesn't really appear to serve a purpose in the cap's strength, so you could probably shed some serious weight there.

All of this is based on the photos, so if I'm seeing something wrong, let me know.