I am astounded ! I did a 200 mile trip some highway at "ludicrous speed" and some stop and go . The 408w got 22 mpg ! Combined . I think thats amazing considering my beater 97 Grand Prix (yuk and no fun ) gets only 23 combined same driving! Granted I cant achieve the same speed or smiles per mile , twice or more power roughly same mpg .. Chris , your system really works well. Cheers all , bob