Do you always drain 8 quarts?

[benhogan]

I changed the oil yesterday after driving the car for a couple of hours. I let it drain for 4 hours with the oil filter cannister cracked open.

Granted, that it was 36 degrees and the oil on the dipstick was at the mid point, I was only able to drain 6 or so quarts.

It's a little disturbing. How much oil does it take from the mid point to the full point on the dipstick? Has anyone ever measured it?

I guess the used oil filter itself 'holds' a quart?