Since we all pretty much change oil before the oil's E.O.L., if oil needs added after O.C.(leaks, burning, etc.), then why not save some used filtered oil from previous O.C. to top off?
Originally Posted By: KingCake
Just run a longer OCI ya dingus.
Without records of UOA's you don't know when that is... and your not saving anything on UOA's(unless you get them for free) just to save money on oil cost.
I used to have a civic with nearly 300k miles on it. It used a quart of oil every 1,000 miles so I changed the oil in my other vehicles sooner and put their oil in it. That civic was pretty worn out at that point and eventually one of the cylinders did stop working.
I would just buy a cheap (and fresh) jug of generic brand mineral oil and top up with that. I use to buy Woolworths / Kmart brand 20W-50 to top up an old oil burner of mine. At least I knew that I as was adding to (not subtracting from) the TBN in the sump.
I use my catch can for all sorts of fluids so I don't want oil mixed with ATF & PSF being poured back into my engine. I always have .5 qts left over during oil changes and that's usually enough for my top offs anyway.
Originally Posted By: Vern_in_IL
Originally Posted By: KingCake
Just run a longer OCI ya dingus.
Without records of UOA's you don't know when that is... and your not saving anything on UOA's(unless you get them for free) just to save money on oil cost.
You only need to do a UOA once to establish OCI. Maintaining records is free.
Originally Posted By: 901Memphis
If an engine is using 1 quart every 1k you don't need to change the oil, just the filter when it's time to remove the built up insolubles.
I've been tempted to do this before with other oil burners. Does sludge build up in the pan eventually and/or is NOACK a bigger concern?
Originally Posted By: KingCake
Originally Posted By: 901Memphis
If an engine is using 1 quart every 1k you don't need to change the oil, just the filter when it's time to remove the built up insolubles.
I've been tempted to do this before with other oil burners. Does sludge build up in the pan eventually and/or is NOACK a bigger concern?
I'm sure it varies by applications but in theory 1 quart of oil every 1k is essentially changing the oil just slowly.
You're replenishing the additives and the TBN and the oil filter will continue to trap particles so everything should be fine doing this.
I can see some things sitting on the bottom of the pan if the pickup won't suck them to be filtered but you could always drain the pan every 3 years and see if anything looks off. In this situation it's gonna be a beater and the engine will likely last longer than the rest of the car.
Why would you even think of doing this? I still got a small stash of $1 Autozone clearance oil and plenty of $2 synthetic Autozone oil. It's bad enough having to find room to store all of it, I'm not going to keep used oil around.
My daughters car is an oil burner, and she never checks it. When she comes down here, it's always low, so I use some of my used motorcycle oil, I change it early, so plenty of life left in it....and I don't have to buy oil just to top up her car.