According to the 1998 Ford Crown Victoria Owner Guide :
With engine oil filter change :
( 5.0 U.S. quarts of 5W-30 )
Four cylinder needs five quarts, six cylinder needs six quarts.
Four cylinder needs five quarts, six cylinder needs six quarts.
Four cylinder needs five quarts, six cylinder needs six quarts.
Four cylinder needs five quarts, six cylinder needs six quarts .
Four cylinder needs five quarts, six cylinder needs six quarts.
Four cylinder needs five quarts, six cylinder needs six quarts.
Four cylinder needs five quarts, six cylinder needs six quarts.
Four cylinder needs five quarts, six cylinder needs six quarts.
Four cylinder needs five quarts, six cylinder needs six quarts.
Four cylinder needs five quarts, six cylinder needs six quarts
Four cylinder needs five quarts, six cylinder needs six quarts
Four cylinder needs five quarts, six cylinder needs six quarts.