Shelf life of oil ??

[bluevelvet]

I am helping a friend with an Escort xflow.....we are about to change the engine oil and filter.
The oil has been in the car for about a year, despite relatively low mileage, we are more concerned with acids building up degrading the oil, even though it looks fine, hence the need to change.

The question I have, a new 5 litre container of the correct grade oil was opened to top up the car last year,,,,,there is 4 litres left in the can,,,will this oil have degraded in anyway by exposure to air over that year or will it be ok to use it for this oil change?

[That Daddy]

Cant see any problem there,oil tends to start going off soon as its in the sump and even more so when you have the by products off combustion blowing past the piston rings(running the engine)but your idea is fine

[bluevelvet]

Cheers, just wanted to check...it's not as if it's had any heat passing through it or pushed around under pressure over carbon deposits to spoil it.

[falcemob]

Providing the lid was on the container and it was sealed reasonably well it'll be fine.

[stigmundfreud]

how can oil have a shelf life (if not used)?