Changed the GC oil out today, at 5150 km. Used the empty wiper fluid bottle which I marked in litre increments just so I could see how much oil I poured back in from the pan. I poured in 4 litres to start with, and smells and seepage on the valve gasket aside, the amount in the bottle was about 250 ml shy.. which means the rest of it was inside the filter, and sticking to the walls of the engine. So none lost at all that I could tell. I was surprised. I won't be using GC again, I didn't like it. It felt too thick in my car, and when starting up my car, I could hear brief noise. Poured in some yellow bottle Pennzoil 5w20. Car runs smooth enough, doesn't seem to make any noise. Doesn't rev up quick yet, but the ECU needs to learn the new oil plus I'm troubleshooting a driveability issue. So we'll see how it goes! I was thinking I would use 5w20 during warmer months and switch to 0w20 Mobi1l during winter months. One scare I had was when looking into the pan I saw quite a few glittering particles. But after I drained it, I stuck my finger into the residue and grabbed some off and looked at it. It seems to not be metal, but silica or salt grains instead. So I think all it is, is dirt from the garage as the pan was facing outwards by the ground. So it goes.