Engine oil Mobil or OEM Audi

Mobil 1 0w-30 AFE has the correct certification, I just used that. Easy to find.

This is a late response but I just saw your post and it's exactly what happened to me when I took my 2018 GSW 1.8 TSI 4Mo in for the 20k mi service. They filled it with 508 00 0W-20. I didn't catch it until much later and I changed the oil myself at 27k mi with Mobil 1 502 00 VW approved 0W-40 oil.

I did my own oil/filter change at 27k mi with Mobil One European Formula 0W-40, since I'm a little uneasy about 10k intervals in So Ca stop and go traffic and 100+ F heat.

I run the 5w-40 in my 2004 Audi A8 and both of my power strokes just because it's handy and the diesel grade oil is overall better than the other synthetic I was running in a 0w-40 weight.

I've been using 0W40 Euro Formula from Mobil 1 for years in both my cars. You will be fine running it.

As a Mercedes-Benz guy, I've used Mobil One European Formula 0w40 in them for decades. It is very good oil. I have well over a million miles on Mercedes-Benz cars using that oil with the extended (10K-15K mile) change interval with zero issues. Several of my cars have gone over 200,000 miles.

But if you want the short of it:

ANY high mileage full synthetic 5w-30 oil will do great. Mobil 1? Sure. Amazon Basics? Hell yeah. Wal-Mart's Supertech? Send it.

I dropped some 0W-30 Mobil 1 this winter, and my sol with a d15b7 loved it. Made cold starts very smooth, and noticed no reasons not to continue running it.

I've used only 5w30 full synthetic (usually Mobil 1, sometimes others) since I bought mine 15 years ago (D15B7). Using the high-mileage variety nowadays, supposed to help out the old seals etc. Just over 150k miles but engine runs very smooth so seems to be doing the trick.

I just did the chains + headgasket and a bunch of other misc stuff on my Corrado earlier this year. My guides were worn pretty bad and it only had 120k on the clock.