What is the difference between old engine oil and old gasoline and how it affects a car

Question

This happened in the mid 1990s and something made me think of it right now.

A family friend ran out of gas 3 blocks from his house. I think he was driving an early 1970s car (if that matters). He walked back home and got gas he said was in a metal canister for at least 15 years to be able to drive the car home.

A few days later, the car didn't start. He said it was his bad because the gas had chemically broken down after sitting in the canister for 15+ yrs and messed up the engine. He fixed it by flushing his engine out several times and all this rust came out of the engine.

Fast forward to the 2000s, I bought tons of oil one Black Friday b/c I thought it was a good deal. I've been putting this oil in my cars for the last 15 or so years and nothing has happened to my engine (knock on wood).

My question is what is the difference between old gas and old engine oil? Why did the gas mess up his engine and cause the car to not start but old engine oil didn't/doesn't mess up my engine?

Answer 1

Gasoline will degrade to a greater extent and you can purchase fuel stabilisers for engines that will be stored over winter for example.

Engine oil does not degrade over time to the same extent or at the same rate so if the oil is not exposed to the atmosphere ie it is in a sealed can then it may last easily tens of years - maybe a lot longer...