The gas formulation makes a big difference.  When I went from Delaware to
the Shenandoah National Park in Virginia, I got 19 mpg.  On the way back,
with the good Virginia gas, I got 22.5 mpg.  Delaware uses the
reformulated/oxygenated gasoline and Virginia doesn't.  It beats me how
burning alot more gas will clean up the air!  I suspect the formulation,
along with the bigger "gallon" is why the mileage is better in Ireland.

                                                             Jay '85 Westy