Good point, it makes sense to compare apples to apples, and that's the efficiency of the vehicle itself. That's awesome that you're able to generate your power with solar and wind dave. I wish I had that capability. I'm not trying to discredit the awesomeness of electric vehicles (seeing as how I drive one), I just want to be fair in how I represent mine, because I am still using fossil fuels, and I'm willing to bet that the majority of plugins are as well. But you make a good point Ben about the well-to-wheel efficiency being a very complicated issue and it seems mpge is the most cut and dry method of comparing two vehicles.
Still, just because a vehicle CAN operate on renewables doesn't mean it does. Crap, you can run most newer gas engines on straight alcohol or a number of different mixtures of renewable substances if you want to, you still get to choose where your power comes from, but most people choose not to
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