Biodegradable this safely removes spills from your pavement or driveway. It is a very reasonably priced cleaner concentrate for the job at $12.79 for one gallon. Removes oil, grease, grime and most stains. You can use this in a pressure washer or manually.
http://www.sunterra.us/servlet/the-79/Simple-Green-Presure-Washer/Detail