Anybody buy any FD-4617's lately....? It seems the frame mount filter has a new grey o-ring, I wonder if its because of the Bio Boom?

 

I have not heard of any change. I still have about 4 sets on the shelf so I don't think I will find out anytime soon.

 

Seems the ones with a 2012 production rate have the gray o-ring

 

This could be interesting, subscribing for details.

While it could be to better handle bio, I suspect it's due to a change in supplier or other sundry reason. Bio was out there before the 6.4L came around, and it's only a little bit more common now.