yeah, they both say to add it right to the crank, then start the car and let it idle, then drain/change oil/filters.

 

How often do all of you do this?

I just used a fuel system cleaner added to the gas tank. That's supposed to clean the valves and injectors, but this sounds like a more thorough solution.

 

You shouldn't do it to often. It puts a strain on your gaskets and seals. Its meant to be used only when needed. My car has about 110,000 miles on it so I figured there would be a little build up of junk inside it. I wouldn't use it any more than every 50,000 miles.