hexl-options

hexl-options is a variable defined in `hexl.el'.
Its value is

"-hex "

Documentation:
Space separated options to `hexl-program' that suit your needs.
Quoting cannot be used, so the arguments cannot themselves contain spaces.
If you wish to set the `-group-by-X-bits' options, set `hexl-bits' instead,
as that will override any bit grouping options set here.

You can customize this variable.