I am new to this board and have been reading a lot about oil change intervals and FSS. I have a 1998 E320 with 60k miles and been changing oil according to FSS every 10,000 to 11,000 miles always with dino oil. Until last year the car was under warranty and I had the oil changed at MB dealership. I remember 2.5 years ago when my car was at the dealer for service my service advisor called to ask if I had a preference for dino or synthetic oil. I decided to stay with dino since this was what I used before. The service advisor never mentioned anything about the benefit of using synthetic oil. However, I did noticed that my FSS was set to 10,000 miles

Now, does this mean my engine is already damaged? If so, what are the symptoms and how can I know the extend of damage. Also, how can I find out if the extended 150K engine warranty applies to me.

S.