So I Saw Castrol Edge on sale at tesco, wanted to buy it but when checking the specs , it has DEXOS approval but no ACEA A3/B3 or B4. I always switch between Mobil 1 0W-40, Shell Helix Ultra 5W-40 and the API SM Castrol Edge FST 0W-40. Why does the old SM have ACEA A3/B4 approval but the new one dont have this approval? Perhaps ACEA C3 is similar ?