FYI Is old oil OK to use?

[J&JD]

My dad had a small shop in Fresno where he built and operated different types of farm equipment powered by all types of engines including old 7 cylinder radial aircraft engines and all types of 4/6/8 cylinder standard automotive style engines. In the early 1950’s he purchased a batch of 55gal drums of reclaimed oil from the Navy that was returned from the Pacific theater after WW2. He used that oil for as long as I can remember (at least 20+ years) in every conceivable engine imaginable. Never once do I remember an engine freezing up or destroying itself because the oil went bad.
Now, does that mean that I would use that oil today in my ISL450? Hell no! However, if I did, I would bet the engine would manage to get to 100k miles just fine. After that…..hmmmm, not willing to chance it with the price of these engines at $50k or more.

 

[Kevin D Pem]

I would suggest doing what you're comfortable doing!

In the early 80's I was using synthetic aircraft oil! I attribute the 250+k miles I put on my old junkers,to that oil! More than likely though,it was the way I drive, but who can say?

That said! If you have old synthetic you don't want to chance, I will use it!!! Well,if its 5 20w

 

[Joe Hogan]

Regarding changes in engine technology and chemistry of fluids, here is an example of why it is important to understand your engine and the chemistry of fluids.
Also if your fluids are Mfg approved can avoid warranty issues.

How low-speed pre-ignition can damage your direct-injection turbo engine - Hagerty Media

LSPI can result in catastrophic engine damage under the right conditions. Conditions I witnessed first-hand when my brother's Focus ST.

www.hagerty.com