Coolant Replacement Schedule?
 

I have a 2011 50i that just hit 50k miles and it's coming up on 6 years of age. I don't see anything in the Service and Warranty Booklet regarding a factory recommendation as to when to replace the coolant. Did I overlook it?

I also did a forum search and I see some discussion of this for earlier model years, but nothing for the 2011 model year.

Can anyone point me to what the factory recommends on this?

Thanks in advance for your help.