Thanks for adding the "Watt Hours Per Mile" into the calculator tool.
However, I have found a bug in it. It seems to work fine converting miles per gallon into watt-hours, but not so good converting watt-hours into miles per gallon.
Usually, if I go straight to the calculator (no info entered in it yet) and put in a number for watt-hours and hit CONVERT to see what it equals in MPG, it will come up as ZERO on some of the boxes and INFINITY in others.
When there is now data in the other boxes, and I change the Watt-hours to something else, it sometimes comes up with the correct number in MPG and sometimes comes up with something TOTALLY OFF, like 8 mpg
It also gives different numbers depending on if I click on the convert button or if I just hit the TAB key to update!
I tested this in Safari 3.2.1 and Firefox 2.0.0.20.
I also noticed that entering the same # in WH came up with different MPG #s in the two browsers.
I love the idea of using this calculator for electric to gas conversion, but it still needs some work!