> I think you are optimistic. If you peg a Vanagon at 55 mph, I think
> you
> will find you will get the best MPG available for that vehicle. Just
> IMHO.

you are correct, ol' Kaolin-breath. :)

remember that little computer-thingie on the dashboard of the blue 88
bus?
when i did the testing of mpg vs mph with it,  the calculated
reference speed of 55.6mph (at steady 3400 rpm) gave out an averaged
mpg of 22.3.
notice that 3400 rpm is just a tad above the max-torque rpm for the
2.1 waterboxer engine. so you've got a little margin of torque to get
you up small hills (molehills) on the highway. problem is, if it's a
bigger hill, you're either going to have to shift down into 3rd or lug
the beast over the hill in 4th, which drops the mpg dramatically.

anyway, for funnsies sake (assuming full tank for the range part) ...

3200 rpm = 52.3mph = 21.9 mpg = 2.4 gallons/hour = 348.4 miles/tank
3400 rpm = 55.6mph = 22.3 mpg = 2.5 gallons/hour = 354.3 miles/tank
3600 rpm = 58.9mph = 20.8 mpg = 2.8 gallons/hour = 331.0 miles/tank
3800 rpm = 62.1mph = 19.2 mpg = 3.2 gallons/hour = 305.8 miles/tank
4000 rpm = 65.4mph = 19.8 mpg = 3.3 gallons/hour = 311.5 miles/tank
4200 rpm = 68.7mph = 18.8 mpg = 3.7 gallons/hour = 301.6 miles/tank

kinda interesting that 4000 rpm actually calculated out (averaging the
4-5 runs i did with each rpm) to better range and mpg than 3800 rpm.
go figure. all bad tests? dodging too many trafficers on the road?

all these tests were done in the summer, with a 1988 vanagon gl
4-speed transmission, on interstate highway that was very flat for
about ten miles,using a Zemco ZT-4 digital trip computer.

have fun. :)

unca joel