Chevy Volt to Get 230 MPG Rating? August 11, 2009 by steve Leave a Comment The old sKeptiK in me is warning caution on this. Can GM really make this? Will it be affordable? Battery life, etc. However, if this comes to market, we all win. Chevy Volt to Get 230 MPG Rating . UPDATE (11/28/2010): U.S. EPA ratings have come out and have given the Volt a 90 MPG (average) rating.