My mileage is consistantly off by 10% or so. I use the trip fcd for segments, but I use gas+miles on the odometer for my actual tank calculations. In my database entry I have been putting in what the car said in the fcd in the notes, but using fuel used and miles driven for my calculations for the tank.

Also, I have heard that over 65MPG or so the fcd starts to be pesimistic vs the optomistic at below 65mpg.

Generaly I take 10% off the numbers when I tell people what I get for a trip unless it is over 65mpg.

My hydroponics experiment

You ever notice how hard it is to lip read cartoon characters?
"Crazy is what the sane call Delta Flyer"