2018 MB GLC 43 (M1 Euro 0W-40 UOA)

[oil_film_movies]

It does seem like the VII chemicals in Castrol 0w40 do hold up better than M1 0w40's. Castrol would be my choice. If I drove it hard, I'd go to a 5w40 229.5 oil instead of 0w40 (TX climate too). Thicker base oil than in 0w40.