My 05 BC has never showed more then 42-44 mpg since the 12K service, when pre service BC showed 47-49 mpg.
actual (on odometer) Average miles/tank is 290-300 consistent tank to tank. So I just ignore BC numbers. I use a small squirt of startron additive on most fill-ups. There is a marina ( I even saw a boat there) close by that sells ethanol free fuel, and it can be purchased in a container that will be removed from the site. They presume it will be for boat engines. (I am told they have some rules) when a friend asked if they had a container he could borrow for a few min. they just laughed. Have not filled up yet with this but will report if there is any great improvement.
actual (on odometer) Average miles/tank is 290-300 consistent tank to tank. So I just ignore BC numbers. I use a small squirt of startron additive on most fill-ups. There is a marina ( I even saw a boat there) close by that sells ethanol free fuel, and it can be purchased in a container that will be removed from the site. They presume it will be for boat engines. (I am told they have some rules) when a friend asked if they had a container he could borrow for a few min. they just laughed. Have not filled up yet with this but will report if there is any great improvement.