A friend has an unopened Quantum PD Diesel 5W-40. As he's had it for about three years, will it still be ok to use?

This came up recently - hope it helps.

http://briskoda.net/general-car-chat/does-engine-oil-ever-go-out-date/148544/

I am interested in this as I have some Diesel in the garage that's been there for a couple of years. Does anyone know if there is a shelf life for this, wold it be the same approximately as engine oil?

I had some oil lying in the gaage for a few years (I think about 5/6) and it ended up looking like Diesel in the container with some thick sludge in the bottom, not hard to work out it needed chucked but this was the forst time I have seen this.

Oil has been under the sea and land for millions of years, it's still there.

2 years shouldn't be a problem.