Oil Change DIY discrepancy
 

I bought the Mityvac 7201 fluid extractor. I have a 2.0 C7, so the oil filter is easily accessible and I saw that I could siphon out the oil from the dipstick tube so I did it myself.

The thing is, the Mityvac only got out ~2.3quarts of oil after air started gurgling (oil temp was ~140F). My MMI had given me the Add oil warning, and in the past when I have topped it off it takes 1 full quart of oil to go from the low level indicator to full. So, doing the math, 2.3quarts extracted, plus 1 quart that I was low on already, that's 3.3quarts. I thought the 2.0 had an oil capacity of 4.9quarts? Where is the rest? I made sure to insert the Mityvac tube all the way to the bottom of the dipstick tube.
Even more, I was so suspicious the first time I extracted it, that I decided to put that oil back into the engine and move the car to a more flat surface, since I it was sitting in a slight incline. No difference, same 2.3quarts came out. At that point I decided to continue and added 3.3quarts of fresh oil, changed the filter, read the oil level from the MMI and it said it was full.

I went into Amazon and ordered a dipstick, should arrive Monday. Not sure if the MMI reading is off, and it's telling me the level is full when it's missing ~1.5quarts, or could it be that the Mityvac didn't get it all out? Any thoughts are appreciated.

FWIW, I've done it 3 times, and usually get a bit over 4 qts, and like frienando above, some fiddling with tub is required.

Fluid extractors depend on drawing and maintaining vacuum in the siphon line to operate properly. Air bubbles in the line at the start or entry during transfer will defeat the flow. This is a fragile process no matter what extractor is used. There are all sorts of ways that air can enter, poor initial vacuum, tube exposed in the sump etc etc. The procedure is not as foolproof or convenient as some people say. You need to be present during the withdrawal the entire time, watching, jiggling the tube etc. It takes me about 15 min. to just siphon. Adding setup, cleanup etc the job is about 30 min. and not as convenient or tidy as a bottom drain (but only if your car is set up for that). With a bottom drain you can open the plug and walk away to do other things. It takes me less time on the Dodge van using bottom drain than the top extraction on the Audi. I use a Topsider extractor which is all metal, squat, relatively heavy and stable. I can imagine light, unstable units will require more time/patience. It does not have level indication, a disadvantage. Why some users here overpraise this thing is a ?. But given the Audi arrangement under the car, top extraction is without question the way to go.

I've done three changes on my 2011 3.0 and it was a breeze. I had no problem finding the bottom of the sump and siphoning out the 7+ quarts. I haven't done my 2016 Audi that doesn't have a dip stick. That will be a little tricky making sure I don't overfill. I'll probably start out seeing how much I extracted with the markings on the Mityvac and then putting that much back in and then checking the MMI.

Anyone know if the dipstick is the same on the 2011 and 2016? If so, I can change the oil on my 2016 when my kid's 2011 is in town.

I put a wrap of electrical tape around my suction hose to use as a guide.

Don't push on the tube too hard after it bottoms out. One guy did and it kinked. He had to drop the oil pan to extract it.