Over the last year of driving I've seen my wh/mile (from the wall) increase significantly. It started at a consistent 250 and is now up around 333. I attribute this to aging/replacing batteries and unidentified mechanical issues.
At the same time, my charging cost has dropped significantly so I did some refiguring on my MPGe.
There are at least 2 ways to calculate MPGe:
Method 1 is more textbook and less variable, using the EPA energy
equivalency of 1 gallon = 33.7 kWh, so 33.7 / Wh/mile = MPGe
Method 2 is much more variable, but also much more relevant and uses your actual cost/mile compared to the cost of a gallon of gas, so $/mile * your alternative gas price = MPGe
A year ago both methods were about the same at ~135 MPGe
Now method 1 gives me ~100 MPGe and method 2 gives me ~200 MPGe
Last edited by Ziggythewiz; 04-23-2012 at 10:15 AM.
Reason: Bad memory