Used twice for Audi A4 B8 oil change. If oil is cold or warm, it will drain very slow but once oil is hot enough, it will do its job very well. You do not have to very handy to use this. This will save you a lot of money from stealership. In fact, some Audi dealership uses this method when they perform oil change. Residual is very acceptable compare to traditional oil change method. Highly recommended.