A recent thread linked to a U of M (boooo... Go Bucks!) study of aerodynamicys of pickups.
Bed cover +++
Open tailgate -
Closed tailgate +
Bed cover made the biggest difference.
Surprisingly tailgate up does better than tailgate down, they say tailgate up creates a bubble of slow moving air in the bed, that is similar to a bed cover. Air spilling over the cab glides over this bubble
A forum community dedicated to Chevrolet and GMC diesel truck owners and enthusiasts. Come join the discussion about duramax engines, performance, builds, modifications, classifieds, troubleshooting, maintenance, and more!