FWIW, I've noticed the same thing when driving my truck with thte tailgate down. No significant change in energy consumed. A belly pan on the other hand DID make a measurable difference, somewhere around 3% to 5% IIRC.
Geoff Shepherd wrote: >Hi Eric, > >Since you were wondering about tonneau covers and aerodynamics, I did some >testing with my factory Ford Ranger Electric and an OBD-II diagnostic tool. >The truck typically uses 60A (@325v) to cruise at 60 MPH. Removing my heavy >fiberglass tonneau cover did not change that. Further, driving with the >tailgate open also did not change the consumption. Now I'm enjoying having >an open truck bed so I can use it as a pickup as intended. I'll probably >sell the fiberglass cover. If I ever add a cover again (to keep rain/prying >fingers out), I'll likely go with a Pace/Edwards Rolltop, which I have used >previously with good results; it is far more convenient than a rigid cover >or typical snap-on soft cover. > >-- >Geoff Shepherd > > >On 9/2/02 11:39 AM, "Eric Johnson" <[EMAIL PROTECTED]> wrote: > >(snip) > >>I've suspected that the open PU box is not very aerodynamic, >>and I think this really shows it. I've driven nearly that distance >>at somewhat lower speeds with less problems. Either the pack >>has weakened greatly in the 6 or so weeks since then, or the >>slightly higher speeds really increase drag. One thing I want >>to try is a tonneau cover. Hopefully, Sheer will post about >>his observations on this subject based on his trip from/to Seattle. >> > > >
