I would suggest you change to a car multigrade oil like 15w40. It is 15 viscosity in cold weather ie thinner so will make starting easier but thickens up to 40 when the compressor warms up giving you full protection in all temps.
Monograde oils are ok in hot countries or in a permanently heated workshop or plant room but not in an unheated shed in the UK.
I was thinking along the same lines as you, modern motor oils are almost designed to hold particles in suspension ready to be removed by the oil filter.Compressor oil is detergent free normally...
Engine oil is full of detergent.
Not really suitable for an air pump - you might get away with a piston pump but not a rotary air head.
Hi
I changed the oil today and it kept tripping the breaker. I double checked the oil and found out it is 40 SAE.
Can I go down to 20 weight over the winter?
Thanks
And yet, as I mentioned elsewhere in this section, my new comp handbook specifically says a multigrade fully synth engine oil is fine. Indeed, it's near the top of the list of preferred replacements. The top one, of course, is the maker's own oil, doubtless produced by squeezing palm nuts between the thighs of ducky maidens, going by the price of it.