Using USED oil as a top off?

[WishIhadatruck]

I put my vote behind the logic used by some others already. If you believe you're draining out good oil that can be used again, leave it in and do a longer OCI! If you believe it is no longer good enough for your engine, drain it out and recycle it.

How can you make sense out of any other position? Is the oil still good or bad? If good, why take it out to put it back in again? If bad, why would you even think about putting it back in? A UOA would be helpful in deciding if the oil was good or bad, but it would never make sense to take it out of a car just to put back in again.

Now if you had a car that you wanted to change the oil while it was likely still good (like a car you store and drive very little), it would make sense to re-use that oil in something else as top off. But to take it out of and put back in the same car, no logic in that.

 

[GaleHawkins]

If I had something like the 1953 Chevy PU we had when I first started driving that burnt a quart every trip into town and back (40 miles) I would be OK using the used oil out of some of my engines today.

Orschelns Farm Store typically has 5W-20 through 10W-40 synthetic blends once or twice a year that meets Ford and other specs for gas engines for $1.99 a quart vs. the regular $3.59 so I stock up.

In today's engines I do not use used motor oil. Oil is better today but the oil works a lot harder too in my view.