Seals and engine life?

[Titan]

Seals usually eat fish and other sealife, so I don't think either of these oils will affect them. (I'm curious what the experts will say, too. Obviously, I'm no expert.)

 

[GoldenRod]

This is a hotly debated topic on this board. Myself....I'm about worn out from this topic. You might check out this thread: http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=42;t=003091

 

[wn1998]

Is there any difference in the chemistry of a group 3 syn and a Group 4 or 5 that would make one better over the other. Is one easier on the seals or does one prevent consumption down the road? I am looking for any difference at all.