I’ve been using an oil extractor with my GTI for a couple of years.
I’ve seen several comments from the internet from people who don’t use these because they want to be sure that they get all of the oil out of the oil pan.
I had read some of these comments recently and remembered them as I started an oil change. I decided to operate the extractor as usual and then raise the front of the car to drain the last bit of oil through the drain plug.
As I backed the plug out of the pan I was anticipating the excess to begin running out, but when the plug was removed nothing drained out. Not a drop.
Hmm. I wondered if this was a double-walled metal oil pan that somehow retained the remaining oil inside an inner chamber.
One way to find out.
I had some extra conventional oil on hand so I poured some of it into the engine. Sure enough, a moment later it began draining out of the oil pan.
So there wasn’t any oil in the oil pan after using the vacuum extractor. The extractor had done an excellent job of removing the used oil, as good as I would have if I had conventionally drained the oil.
An oil change was performed on my Mk7 GTI using an oil extractor and following the removal of the oil with the extractor the oil pan drain plug was removed. No remaining used oil was found in the oil pan.
The oil extractor does a satisfactory job of removing used oil from the Mk7 GTI oil pan.