RE: Does anyone use Mobil Jet Oil II?
Revision F of MIL-PRF-23699 adds a C/I (corrosion preventative) specification for qualification to MIL-PRF-23699.
This revision has nothing to do with lubrication qualities, low/high temperature limits, etc.
Any oil qualified to MIL-PRF-23699 (any revision letter) is acceptable for use in our engines.