Maybe a daft question, but does anyone know the 'shelf life' of the average oil filter? The reason I'm asking is because I recently found one at home that I'd bought and then mislaid and forgotten about. It's about 3 or 4 years old. Is it ok to use this one at my next oil change or will the filter media have deteriorated?

I would think that if the thing can deal with hot nasty oil running through it then it can probably cope with some air for a bit. Worth looking at the paper through the holes if it's the can type device.

I guess I'd be concerned if the paper inside it had been exposed to water which would probably soften it up.

Agreed. I'd discard it if the box it came in was water-damaged, but otherwise I can't see any reason why it shouldn't store more or less indefinately. Also, if it's one with a silver crimp ring and/or an unpainted mating face, I'd discard if there was any sign of rust on them.

Thanks for your thoughts guys. The filter was in the shed, which is reasonably water-tight. However, on balance, the price of a new filter is a pittance compared to the cost and hassle of major engine work if it fails. Since I can't be sure that it was never affected by moisture, perhaps I'll splash out on a new one.Again thanks for your advice.

I am still using oil filter stock fom 1983 - no problems at all.

Those are 26 years old! I'm impressed. It probably would be ok then. Thanks for that Tailhappy.