Reusing oil, a thought that crossed my mind.

[Duckless]

Alright, I'm not going to do this, just creating discussion. Let's get that out of the way.

I see it a lot on here- people claiming this oil or that oil (let's go with HPL here) is a long drain oil and "if you're changing it at a 5k OCI, you're throwing away money". Then you see claims (and probably proof as well) that these oils clean up motors and do great work.

What would be the harm of i did a 5k OCI to clean one motor, drained it and put it in another motor to also run to 5k and clean that motor? Most of the crap is picked up in the filter, with of course junk also suspended in the oil. But the junk in suspension was going to be there and acceptable for the other motor if it was ran to 10k.

Edited to add: this is assuming lab levels of clean for the drain, the pan and swap,.no contamination there.

So 10k total use out of the oil, and two cleaned up motors. Win win?

 

[JavierH19]

I wouldn't say so since the esters will deplete in the first engine quickly since it's going to do more work when it's all in one engine and expend fast and not leave much for the next run. It's better to just split what you have and mix it with something like m1 0w-40 and run them both for a full length. Or you can use valvoline restore and protect which although has no esters and a standard detergent package seems to do something special in terms of cleaning as is slowly proving. Many have cut filters after using it for a run and it undoubtedly cleans more than the normal oil.

 

[MolaKule]

Alright, I'm not going to do this, just creating discussion. Let's get that out of the way.

I see it a lot on here- people claiming this oil or that oil (let's go with HPL here) is a long drain oil and "if you're changing it at a 5k OCI, you're throwing away money". Then you see claims (and probably proof as well) that these oils clean up motors and do great work.

What would be the harm of i did a 5k OCI to clean one motor, drained it and put it in another motor to also run to 5k and clean that motor? Most of the crap is picked up in the filter, with of course junk also suspended in the oil. But the junk in suspension was going to be there and acceptable for the other motor if it was ran to 10k.

Edited to add: this is assuming lab levels of clean for the drain, the pan and swap,.no contamination there.

So 10k total use out of the oil, and two cleaned up motors. Win win?

There will always be particulates in used oil, some very small. An oil filter will only trap particles down to a definitive size.

But particlates are only half the story. I think we're forgetting here about the degradation of the additive package after it has been subjected to the combustion environment.

Addendum: One also has to consider that the oil may have been contaminated with fuel and moisture.

So no, I don't think this would be a viable practice.

 

[kschachn]

I wouldn't say so since the esters will deplete in the first engine quickly since it's going to do more work when it's all in one engine and expend fast and not leave much for the next run. It's better to just split what you have and mix it with something like m1 0w-40 and run them both for a full length. Or you can use valvoline restore and protect which although has no esters and a standard detergent package seems to do something special in terms of cleaning as is slowly proving. Many have cut filters after using it for a run and it undoubtedly cleans more than the normal oil.

How do esters deplete?

 

[Ride_Red]

Not worth the hassle. Moneywise, you are probably even just running it a full 10K in the one engine.
Do the math on changing two engines at 5K and again at 10K vs just running both engines for 10K on HPL.

 

[nthach]

In gasoline engines, it ain’t worth it. In a diesel fleet, especially with city/school fleet buses, long drains are the norm but those buses have a Spinner II or similar centrifugal or deep media bypass filter to allow for longer drains, getting that soot out is key.

 

[RDMgr]

How do esters deplete?

I was just going to ask the same question.

 

[dnewton3]

Nope. It's a lose/lose.


However, why not use HPL in BOTH engines, and extend BOTH OCIs? That's a true win/win !

 

[Cheetah-kins]

I agree with the 'not worth the hassle' comment. Also my biggest concern would be the oil changing for the worse during it's first run with the high heat and other things that happen during the combustion process. I would think after 5K miles suspended particles aren't the only thing wrong with the oil. Some things are just worth spending the money on.

 

[gfh77665]

Before "not worth the hassle" and "lose-lose" is locked in, lets have some context. If someone runs M1, Edge, or PP or something like that for just 5K miles, it is not used up in 99% of the cases. Those quality syn oils are likely "functional" until 10K in most circumstances.

So it depends on what it might be going in. A 20- 25 year old vehicle in the last 25% of its life, with 250K-300K miles it would work fine.
For everything else? Then "not worth the hassle" and "lose-lose" is correct.

I did this several times with beater trucks. I would add 1 qt. new oil with 4 qts. "Mobil 2" and never missed a beat. There are a number of Mobil 2 threads out there. This is eco friendly, too if thats a concern. If you don't want an extended 10K interval in a new vehicle (regardless of oil brand) have confidence a top quality syn will last beyond 5K in another older, vehicle.

 

[Ausfahrt]

Before "not worth the hassle" and "lose-lose" is locked in, lets have some context. If someone runs M1, Edge, or PP or something like that for just 5K miles, it is not used up in 99% of the cases. Those quality syn oils are likely "functional" until 10K in most circumstances.

So it depends on what it might be going in. A 20- 25 year old vehicle in the last 25% of its life, with 250K-300K miles it would work fine.
For everything else? Then "not worth the hassle" and "lose-lose" is correct.

I did this several times with beater trucks. I would add 1 qt. new oil with 4 qts. "Mobil 2" and never missed a beat. There are a number of Mobil 2 threads out there. This is eco friendly, too if thats a concern. If you don't want an extended 10K interval in a new vehicle (regardless of oil brand) have confidence a top quality syn will last beyond 5K in another older, vehicle.

In a perfect world? Maybe.

Is there debris around the drain?
What are you draining the used oil into?
How are you keeping dirt out of the used oil?

I'm not trying to rain on your parade because I applaude the idea and as you mentioned it is eco friendly. I'm just not sure if it works in the real world.

 

[gfh77665]

It certainly has in my driveway, for many times over many years. Never missed a beat.

Keeping the used oil generally uncomtaminated is a concern, but a speck or two even if it got in would quickly be filterd out. Remember we are talking vehicles on the last 25% of their life. They probabaly had much worse over their lifetimes. I have heard some people simply put a paper filter in the funnel. Easy to do.

I appreciate you being polite, but just for clarity, its not a parade I am leading nor am I really an advocate for this. I am just trying to answer the OP's question accurately. Like most anything, "Mobil 2" oils will work perfectly fine in the appropiate applications.

 

[Patman]

I think that a good synthetic oil that doesn’t get diluted with fuel still has quite a bit of life left in it when many people are draining it at only 3000 miles. So it would definitely be a good idea to put it in another car that’s out of it’s warranty period and run it another 3-5k.

 

[gman2304]

I wouldn’t do it but years ago a long time friend would change the oil in his newer car, then use his drained oil for his High School sons beater. AFAIK his sons car never suffered an oil related problem.

 

[LineArrayNut]

I offered a guy on here, now a moderator, to put his 10k oci incessant posts to the test with my Mobil 2. He said he would, then backed out , blaming possible manipulation. Offered to come to his location, still backed out. Ymmv

 

[BigCahuna]

Why wouldn't you just change the filter at 5k, and run it another 5k in the original engine ?.,,

 

[Hootbro]

When I was young married poor lower enlisted in the Army back in the late 1980's, my next door neighbor had a Corvette he changed the oil religiously every 6 months with Mobil 1 and I would use his drained off oil in my Toyota pickup with the 22RE engine. That oil at best maybe had 200 miles on it when I got it. Did that for 2 years with 5K-8K mile OCI in that 6 months. Eventually got over 275K miles on that truck before it rusted out but the engine would go on to be a salvage pull for somebody else. I do not think that truck suffered anything from the practice but those 22RE engines were tough to kill anyways.

 

[71Chevyguy]

I think it depends on how you look at it. If you have an old car that goes through a ton of oil but still runs great, it would be ideal. I don't think I would do it in a newer car. I used to have a Saturn SL2 that went through some oil, like they do. Had I kept it longer, I would probably have done this and changed the oil filter once a year. But I would have rigged up some contraption to filter the oil as much as possible for re-use. You don't want to pass too much dirt on to engine number two.

A lot of older vehicles couldn't care what oil is in them as long as it was there and not thinner than the OEM recommendation. If using this Mobil2 in a decent car, I would suggest using a quart of fresh oil with the re-used oil. Probably something like diesel oil or Mobil1 0w40 that is very high in additives to "freshen" the used oil up. Or keep it on the side for top ups in vehicles before they are due for an oil change. Any of the newer Hyundai/Kia cars with major consumption problems are a good candidate for that kind of top up.

 

[ATex7239]

I’ve thought about doing this in the Hyundai since it is a high mileage vehicle and isn't driven much. Using the old 0W20 from the Toyota would save some money. But at the end of day it’s only about $20 a year for me. So not worth the hassle IMO.

 

[Rmay635703]

If you have one vehicle that requires some sort of 40wt and the other some type of 30wt and you “extract “ the oil (no drain) and have a way to filter and potentially centrifuge and dry, you might get away with this, especially if some of the oil used in the 2nd vehicle is new due to incomplete extraction from the first.

Lots of work and risk for no good reason.

I am told some folks who use or burn a lot of oil in small gas equipment use “used” oil in them on occasion.

I remember about 15 years ago a place hocking pure group 5 oil with a bypass filter, testing strips and “additives/buffers” you would periodically add to have a “lifetime “ oil change