Topping off with used oil

[lt1man]

There was a thread previously about this. But for those of you that have cars that burn oil and have to top off, I think it would make sense to save some of your old oil and use it to top off when you dip stick gets low between changes.

My Saturn takes 4 qts in the sump, I just used a 5 quart jug of Super Tech 5W30 full synthetic. Anyways, I don't think I'd use used oil to top of my car, but the previous thread discussed using used oil in other vehicles, I just don't recall hearing anyone re-use it to top of oil in the vehicle the used oil came from.

 

[gfh77665]

Thats exactly what I do (with the beaters). I started the "Mobil 2" thread last week, wondering if anyone would say this! It won't hurt a thing!

 

[AVB]

If I was going to put it back in, I would have never taken it out.

 

[poiuy223]

Originally Posted By: AVB
If I was going to put it back in, I would have never taken it out.

/agreed

 

[Donald]

I might get cheap oil, but never used oil.

 

[oggb]

Originally Posted By: AVB
If I was going to put it back in, I would have never taken it out.


Absolutely

Unless you have MANY vehicles and a LOT of used oil (I have about 5-10gal/month) and a vehicle you really don't care about.

I mean jeez, at least mix it 50/50... It's used oil for a reason.

 

[Turk]

Originally Posted By: AVB
If I was going to put it back in, I would have never taken it out.

 

[gfh77665]

Think about a 5K change. Put new oil & filter in, catching and saving about 3-4 quarts of the old oil. Car goes 4000 miles, and it is now 1 quart low. Why put in a new quart that would soon be drained out?

The old stuff probably easily has 1000 miles of life left in it, and would only be 20% of the volume anyway. You save resources and money by reusing that one quart for the remaining 1000 miles.

 

[Malo83]

Never!

 

[dubie2003]

If you use used oil, make sure it is not from the beater. The concentration of contaminants would be too high in most cases.

 

[Stephen_G]

Only time i would use..used oil would be in a lawnmower that consumes it rapidly, and even then if i just need to top it off for one use, and then drain afterwards.

That being said, i normaly top it off with 1/2 quarts of whatever i have lying about, 10W30 5W30 etc, it is old enough where it does not really matter.

 

[Chris142]

Originally Posted By: Donald
I might get cheap oil, but never used oil.
x2.no way would I put used oil back in unless I was broken down out in the desert with no other option

 

[tommygunn]

My "used oil" I consider past its service life. I have used used engine oil to sort of crud-flush a garbage picked lawnmower before installing fresh oil though, but it was basically unnecessary to do that. I did it just because the used oil was this thick slow dripping syrup.

If you're within 3000 miles of your OCI though, regardless of what oil you have in your sump (synthetic, dino, etc), I always top off with the most dirt cheap oil I can find bearing an API certification (30wt, "snowblower oil", motorcycle oil etc, anything, it should all last more then long enough anyways and its only a little so who cares?).

 

[oggb]

Originally Posted By: tpitcher
Originally Posted By: AVB
If I was going to put it back in, I would have never taken it out.

Ahahaha, I missed that completely! Nice catch.

 

[gathermewool]

Originally Posted By: gfh77665
Think about a 5K change. Put new oil & filter in, catching and saving about 3-4 quarts of the old oil. Car goes 4000 miles, and it is now 1 quart low. Why put in a new quart that would soon be drained out?

The old stuff probably easily has 1000 miles of life left in it, and would only be 20% of the volume anyway. You save resources and money by reusing that one quart for the remaining 1000 miles.


Really??? Then extend your OCI. This isn't rocket surgery, man.

 

[Loobed]

I don't think I would even put used oil in chain saw.

 

[dave1251]

If I do not have the same brand at home. I just go to the store buy the least expensive oil that meets the same specs and use that as a top off. Just use whatever works at prices you are willing to pay.

 

[Malo83]

Originally Posted By: gathermewool
Originally Posted By: gfh77665
Think about a 5K change. Put new oil & filter in, catching and saving about 3-4 quarts of the old oil. Car goes 4000 miles, and it is now 1 quart low. Why put in a new quart that would soon be drained out?

The old stuff probably easily has 1000 miles of life left in it, and would only be 20% of the volume anyway. You save resources and money by reusing that one quart for the remaining 1000 miles.


Really??? Then extend your OCI. This isn't rocket surgery, man.

 

[Shannow]

If it's a point worth worrying over, then buy some SAE30, and just top off with that.

I sort of get the argument, as my Nissan tends to lose a liter between 7,000 and 8,000 km, with change due at 10,000km.

There's usually enough left in the bottle that I changed it with, or enough "stuff" in the shed waiting for a home.

Got no issues using a full sump of used oil for a beater, but used in the DD, even for top-off is a bit...errr.

 

[tommygunn]

But if the dipstick is completely dry and you've noticed a slow leak, and you know a short drive to the parts store will get you the fix well...

Then I can understand it (and then changing the oil).