I use comma 10w-4o semi synth,the cars done 94K 18T AGU engine.Dont know what oil it had in before i got it but i tried 5W-30 fully synth and it sounded tinny,Then was told using 5W-30 oil is to thin and does something to the seals near the turbo so i changed to 10w-40 alot quieter and seems ok