Technical Pre-Opened Oil - Any Good?

[Guerciotti]

Hi,
I have about a litre of leftover Castrol Edge 5w 40 oil which I kept in the garage in an old (but washed) plastic ice cream container from last year's oil change.

Well it's time for the 500's yearly oil change and I wondered if it was ok to use this oil or whether it would be 'off'. I know not to use previously opened brake fluid but wasn't sure regarding engine oil.

Cheers

 

[lunchbeers]

There shouldn't be an expiry as such, but depending on how carefully you washed and dried the container, contaminants and detergents may still have entered the oil.

For the sake of the cost of a litre of oil, wouldn't you prefer knowing that all your oil is new?

 

[Ralf S.]

If the container was spotless clean, the the oil is okay to use. Oil doesn't really go off (at least, not in one year).

Even if the oil was not spotless clean, anything in there that was soft, like a bug, will get mashed by the engine and end up dissolving or being trapped in the oil filter.

If you're in the habit of storing metal fragments in your oil containers, it may be best not to use it...

Brake fluid doesn't like being stored because it absorbs moisture, which can theoretically cause corrosion in your brake system and which can reduce the boiling point of the brake fluid... but in the container even that would be in good condition after 12 months. Change the brake fluid every 2 years, once it's in the car. It picks up a lot more moisture there.

Oil is designed to absorb moisture and as soon as your engine heats up, it's boiled off, so no real worries about moisture in oil. If it's cloudy or has white streaks in it, that's probably too much moisture though and I'd use it to lubricate the hinges rather than put it in the car.


Ralf S.

 

[Guerciotti]

Thanks for your feedback