What year is your data sheet? Used to be on there. Link to it?
2014ish when oil company was bought that originally made it. Then new company started making it.
Spectrum Oil Co was bought out by Phillips 66 in 2014.
Copy past from old threads many years ago when others noticed.
(July 31, 2014 was acquired by Phillips 66.
Notice that pre 2014 Red Armor had a slightly different chemical
composition.)
Red Armor contains a polymer
( polybutene after 2014 /polyisobutylene before 2014 )
for making the oil adhere better to the surface of metal parts.
(Red Armor (Shindaiwa and Echo versions) is still showing no ester in the formula according to Phillips 66.)
http://w3apps.phillips66.com/NetMSD...anguage=EN&IssueDate=12/4/2013&SubFormat=USDS
http://w3apps.phillips66.com/NetMSD...anguage=EN&IssueDate=12/4/2013&SubFormat=USDS