PCMO additives settle out and degrade with age?

[Steelhead]

do PCMO additives settle out and degrade with long term storage setting for more than 1 year on the shelf?
what is max. storage time?
how does storage temp. affect long term quality?
are base oil affected by long term storage?

most manuf. info I've seen recommends use in less than 1 year and storage between 40>80d F.

 

[TallPaul]

There are a number of threads on this. There does not seem to be a set time frame. I figure 5 to 10 years if kept from freezing weather and extreme heat. Mine is in cellar ranging 40F to 70F. Shake the bottle before pouring in and any settled additives will be mixed in, not left in bottom of bottle.

Valvoline once told me shelf life is indefinite. What does that mean? They don't know? Forever? Until it degrades?

 

[Triple_Se7en]

We have seen excellent used oil analysis on GC (German Castrol) that are around five year-old products - kept in an unheated garage.