I acknowledge that aviation oil suppliers(shell) says that there oil has a 4 year shelf life. Easy to find when you look it up. Like I said airplanes are nothing to cut corners on.

Then regular car and truck motor oil suppliers recommend a 5 year shelf life.

Years ago our business quit selling motor oil because it was hard to make any money. So we took it out of inventory and started to use up old stock in our own cars and trucks. I am still trying to use it all up since some of it was 20w50 racing oil. I used some of it in my big block dragsters. But then I switched to blown hemis and went with pennsoil 60 weight, so some the 20w50 is still in stock.

This was around 1992-4 that we quit selling it. I have used the 20w50 in both of my muscle cars. I built my last 340 in 2007 and it now has over 30K miles on it. I have posted about the car many times here as I took it on vacations and beat the hell of it at Bonneville 3 different years, drove it in Vegas 2 different years when it was 115°F and had it all over the rest of the country driving it. It still runs the same today and I swear it burns no oil.

Then I built my 440 in 2005 and it still is running today, although it has far less miles on it. Both are running 25 year old oil.

Then I had shell rotella in 6 one gallon cases. I used it in our companys tanker trucks that run DT 466s. I also run it in my Cat C-12 in my toterhome that makes 505HP, that truly is a hi performance diesel engine since 2002. Today it still has 25 year old oil in it. Although there are only 5000 miles on the oil that is in the engine now. On big trucks I change the oil every 500 hours.

Here is the parts from a 2004 DT 466 that has a honest 16400+ hours on it and the first 10-12000 hours were run on 1992 shell rotella, some 15/40 and some straight 30 weight.



Then I have used old oil in many small engines, too many to list and other vehicles too since 1992. So that has been my experience with old oils. Have never had a engine failure and I personally maintain 20+ vehicles since 1983.