You do not mention which driver you are using. V3 or V4. You can save the settings and Earth Smart Printing is available as a Preset.
I hope this helps.
I see no one has responded to this post yet. So, at this point I would recommend contacting your local Xerox Support Department to speak with a Product Specialist for more assistance with making changes to the printer driver. Please call 1-800-821-2797 or 1-800-835-6100.
Is there a draft mode that can be used on this machine for reduced toner usage?