Wow, this is an interesting thread. I consider myself lucky because my LS3 in the Chevy SS takes exactly 2-gallons, no matter how you cut it. Back in 2017 when I purchased the car, I had the free oil changes from the dealership. I took advantage of them on the first two, but each time they screwed things up. After that I forfeited the remaining oil changes and just started buying my own oil and taking my car to the Valvoline lube pit. Besides, it only takes me 15 minutes instead all day at the dealership, plus I get to stand there while they work.