Step one: pick the low hanging fruit.
There's no denying that I will be able to do very little about the gross weight of this beast. Simply not much to be done about it. Even removing 100-200 lbs from a 5500 truck will not be very noticeable in terms of mpg. But my commute is mostly back road cruising, and the aerodynamics of this thing can be vastly improved.
For example:
The truck came with this front wind deflector / bug shield. GONE.
I mostly listen to local radio stations. Don't need the stock 3 foot antenna. I also don't ever plan to renew the OnStar service. Antenna swap!
Capped the OnStar antenna stud:
And put the shortly on the hood:
I think it looks pretty sharp there, actually.
The front end of this truck is a total aerodynamic mess. I plan to seal up all the gaps eventually. Found that some rubber hose filled between the bumper and grill ok:
Vs:
