mpg on my 340

so when I am reading all those numbers.... why do I have such a bad milage ? 340.. 727 and 3.23... TQ carb..
What is the secret ??

Greetings Juergen

And no...I don´t jump in the gaspedal hard !! the 11 mpg
is with 55 -60 mph on the autobahn....