So, are you confused about the presence of two MPG numbers on your newly delivered Volt? Fear not, the folks at GM are doing their best to educate the huddled masses about the Volt's industry-leading fuel economy, and just how the EPA arrived at the car's previously released 93MPG (electric equivalent) and 37MPG (straight gas, homey) ratings. No word on plans for a film explaining where the missing 137MPG