You can use it in the oil to help clean the engine sludge, and also use it through the intake to clean the valves [after which plugs usually need to be regapped and or replaced]. Also you can run it through the fuel system to clean the injectors... There are lots of uses for it, try using search here and you will find many stories here, or google it and find stuff out there in the WWW. Welcome to LOD! MOst people flame you for asking questions and not searching on your own, because search is so full of answers...