delo is great oil and does wonders in m20s and m30s it reduces the valve train noise by a noticeable amount

Quote Originally Posted by pcross View Post
Delo 10W40 is not a high mileage oil. It is primarily a heavy duty oil for hard-working diesel engines. It has no seal swelling additives or other junk like that. I just happen to use it in my high-mileage 525i.