At 12:13 PM 3/28/2015, Dennis Haynes wrote:
>the limit of both efficiency and the edge of destruction. Over the
>years I find it common to get differing fuel economy on trips based
>on direction, especially when mountain ranges are involved. Outside
>temps can also mean a difference.

Every foot of net altitude gain at the end of a trip is you having
dead-lifted the van that high.  On the return you turn that potential
energy back into kinetic, minus the usual efficiency tax.  Hills on
the way with no net gain or loss cost you only the efficiency tax,
unless of course you have to hang on the motor or use your brakes, in
which case you lose some as direct conversion to low-grade heat.

Yrs,
d