Engine oil life .. in an opened container

[Jonny TVR]

I've got a lot of old oil in my garage from cars gone and existing ones. In the containers but opened. How long does oil actually last like this? Some of it must be 3 to 5 years old .. most synthetic.

[Jonny TVR]

[Jonny TVR]

Also have around 25 litres of coolant .. how did that happen!

[Jonny TVR]

Also loads of dot 4 so throwing all of that as not sure how old it is.

[petop]

Military synthetic oil has a re-test date of between 3-4 yrs. They carry out visual inspections of batches of oil every 12 months. I would open it, see if there is any emulsification taken place and if not use it. Otherwise if you have any doubt, bin it.

[HelldogBE]

Jonny TVR said:

Also loads of dot 4 so throwing all of that as not sure how old it is.

As you already suggested there's nothing better than fresh braking fluid as it's hygroscopic (absorbs moisture) and an opened container will deteriorate in a similar fashion to being used in a car. For this reased I buy my DOT4 braking fluid in 1L containers instead of 5L so I can always use fresh closed containers.

As for engine oil life Google suggest 5 years when stored in the garage. I wouldn't worry about that. The only thing that puts me off is not having enough of a single oil type left so I have to start mixing oil specifications. No longer have a car that needs topping off anymore in between services, but I also tried to stick to the same stuff that was already in there. Thus I'd end up with small quantities of 3-4L that I couldn't use for anything other than maybe a lawn mower service.

[GreenV8S]

I'd expect oil to keep practically forever. In use it fails through contamination and extreme heat, and it won't see either of those in storage.

Brake fluid that has been unsealed and resealed will also last a long time although it's unlikely to be resealed perfectly so I wouldn't trust it after a year or so.

Coolant will last effectively forever. It fails through corrosion (the inhibitors in it get used up when exposed to metal surfaces) and it won't see any in storage.