Changed oil and filter at around 185,000 miles.
Ordered 10 quarts of oil on April 7, 2016 and recorded the mileage as 181,815 on April 3, 2017. I didn’t document this one for some reason, so the image is for illustrative purposes only.
I knew the oil had just been changed when I bought the car. At right under 3,000 miles of ownership, I decided to change the oil. It wasn’t a magical interval for me, but it just felt like it was time. I didn’t want to get too caught up in the great oil debate, so I took some direction from the forums and went with regular (i.e., non-synthetic) Castrol GTX 20W-50.
I’ve since started to use LiquiMoly in my Audi RS4, so we’ll see if I change my mind about the M5.