Okay, now i'm thoroughly perplexed why the two ways of calculating give completely different answers! This is gonna trouble me all day now.
EDIT, Okay, this fit's into my assumption that if you get 15mpg going uphill a 1 mile hill, and then coast all the way down with the engine off getting INFINITE mpg for 1 mile, then the most you can gain is double the mpg you had going up, which is 30mpg. But shouldn't mpg be a metric of volume used over distance already?
Which in a hybrid, electricity is always used going up hill, so your recoverable mpg going back down hill is potentially greater because the mpg going up is the factor that will double ideally?
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