Engine oil Shell or OEM Audi

I don’t drive my car enough to hit any of the reasonable mileage points. I change my oil yearly, roughly around the time it gets inspected. Might be overkill (last year the car moved 2k miles, the year before was 2.4k), but I figure the $80-85 I pay is worth it. My wife’s Q7 will be getting its oil changed every 5k miles. It’s a 3.0T supercharged and they love to eat oil, I’d probably add half the oil back just to make it to 10k.

I do every 5k (2013 S4)

Over here in Germany changing your oil every 3k miles in a normal A4 absolutely tanks your resale value. The only reason to do this frequent oil changes is to hide problems. Personally my car did 30 000km(~20k miles) until 91 000km and then every 15 000km(~10k miles). It's a diesel and almost all longish distance highway trips.

I do 5k/3 months. 3 months usually comes first.

In Canada Audi recommends oil changes ever 15,000km. I always do 10-12,000km because I do city driving. My buddy did every 25,000km on his Mercedes Benz and the thing lasted to 400,000km.

5-6k. It depends on how much you push the car. Hard acceleration and high revs will require more frequent oil changes.

As long as you’re not mixing fuel with it you’ll be fine. All of my stuff runs on basic and cheap T4 Rotella 15w-40. Have never had a single issue

Rotella T6 full synthetic, zero problems, never let me down.

Rotella t6 never let me down cannot get it so Schaeffer's it is. As long as you change it you're good. Schaeffer's has a 5w40 which I like because I see thirty below in the winters

I've used a number of different oils in my XS400 over the past couple years, can't say I've noticed much of a difference other than when I used a 15W40 the engine was a lot noisier, going back to 20W50 and the engine quieted down a lot.