Mr. Squirrel, I find it to be true of all my vehicles.  I believe that one reason has to do with the consequences of driving on ice and snow, which means more variable speed.  I also believe that fuel formulation changes for different temperatures make a difference.  The slight difference in fuel density should mean better winter mileage, but I guess the other factors obviate that.  For my Prius, that vehicle runs the engine more to keep everything warmed to the temperature the vehicle's brain prefers.  But that doesn't apply to the Vanagon of course.  mcneely

---- Rocket J Squirrel <camping.elliott@GMAIL.COM> wrote:
> I'm exploring this now. It seems that, without any change in driving
> habits, my van's mileage is poorer in winter than in summer. I'm talking
> northern hemisphere here, and by "winter" I mean "cold" and summer,
> well, not cold.
>
> I'll be checking this for the next couple months, comparing 10% ethanol
> gas v. straight gas.
>
> In the meantime, has anyone else noticed this? Is it common, with a
> simple explanation?
>
> --
> Jack "Rocket j Squirrel" Elliott
> 1984 Westfalia, auto trans,
> Bend, Ore.

--
David McNeely