Some owners' manuals say 5.5 quarts, and some say 5.8. (My 96 says 5.5...)
Either way, I think 6.0 is a safe number, and convenient, too. I think I'm going to start doing this on my next change, for all the reasons noted above.
Function before fashion.
'96 Contour SE
"Toss the Contour into a corner, and it's as easy to catch as a softball thrown by a preschooler." -Edmunds, 1998