Just did my first full fill up on my new (used) car. I picked up a SGII at about 2/3 tank and set it totally wrong.
I was horribly depressed at not even being able to hit 32mpg @50mph
I tried all the driving tricks and it just wouldn't go any higher. Imagine my surprise when I did the math after filling up and saw
44.76mpg!
SGII is set correctly now