Any UOA's of never changed, "top off oil only" vehicles?

Messages
5,282
Location
Southeast Texas
Some have vehicles that get to a point where only the filter is changed periodically, and oil never changed but is only topped off as needed. Most of these are adding a quart every 500-1000 miles. Any UOA's of these?
 
Messages
170
Location
MI
Also depends on when they took the sample. If they topped off first, it would skew the sample.
I had a car like that once. Why put in four new quarts in 5000 miles if you already put in four quarts over the same interval. Makes sense to just keep topping it up. Other than the benefit of a flush with the new oil, the additives and wear particles should stay at an equilibrium level by just topping it off. Same principle as doing a spill & fill on an automatic transmission periodically instead of a full service fluid change at 100K miles.
 
Messages
435
Location
KY, USA
I didn't do an oil analysis but I had an old work car years ago that was burning/leaking a quart about every 300-400 miles. I was topping it off with oil I'd drained out of my better cars at oil change. This was back in the early 90's when I did 3K mile OCI's. When I sold the car it had been over 31K miles since it's last oil change and the person I sold it to drove it another year or two before junking it because it wouldn't pass emissions testing which had just gone into effect in that area. Seeing how it lasted if I had it to do over again I'd do the same thing all over. I think the main thing on a car like this is making sure you keep oil in it and at a safe level.
 
Messages
4,733
Location
Ohio
If the filter was changed routinely, I suspect the analysis could turn out a lot better than people will accept !

Contact Blackstone or one of the other labs and ask. They could possibly provide the data without any details of the owner.
 
Messages
128
Location
Kentucky
I got hired at a factory just out of high school. I became friends with an older guy who was a couple years away from retirement. He never changed oil. He ran 3000 miles then changed the filter and added a quart.
 
Messages
4,871
Location
OK
There's a guy here who uses a bypass oil filter and pretty much just adds oil as needed.. rarely does a full change. Has posted numerous UOAs every 20k or 40k of driving. Can't recall his name though.
 
Messages
2,220
Location
South Carolina
I had a friend who was an Amzoil dealer. He had Ford van that he used for his business with the AmZoil bypass filter. 189,000 miles without an oil change.
 
Messages
2,220
Location
South Carolina
I find that amusing. A guy who is in the business of selling oil yet refuses to use his own product!
It was a rolling advertisement just proving that with Amzoil oil and bypass filter you didn't nee to change the oil. It was (is?) an Amzoil pitch on their website.
 
Messages
6,389
Location
Connecticut
I still find it strange. A business model of buy our consumable product once and never buy it again. Tough to stay in business doing that.
Not really, people will purchase the filters, bypass kits and the oil. You draw them in with the cost savings over changing oil as normal.
 
Messages
1,942
Location
British Columbia, Canada
Some have vehicles that get to a point where only the filter is changed periodically, and oil never changed but is only topped off as needed. Most of these are adding a quart every 500-1000 miles. Any UOA's of these?
I suggest that the result would be different between an oil leaker and an oil burner.

For an oil leaker, the oil and everything it holds in suspension is being replaced periodically. If you have replaced all the oil over a typical oil change interval I can't see why you'd want to replace it. Though it would make sense to replace the oil filter at a typical oil change change interval.

For an oil burner, I'm not so sure. If the oil is getting past the rings, I would hypothesize that only the oil is getting past and being burned and what has been held in suspension is being left behind and would therefore accumulate. The same might be true for oil getting past valve guides. In either case (until there is an oil analysis that showed otherwise) I'd expect that the oil and filter would need changing at some interval, and I'd start with the typical change interval.

I don't know any of what I've said above is true but that's where I'd start the discussion.

Nowadays if I had a vehicle that was leaking or burning oil at that rate I'd do something about that instead anyway. I did have an oil burner in my younger days (Ford 289 V8 with 80,000 miles) and it seemed to burn less oil when the oil was fresh. So I changed it for that reason as well. With modern oils I doubt that would be true.
 
Messages
251
Location
Independence Ky
I suggest that the result would be different between an oil leaker and an oil burner.

For an oil leaker, the oil and everything it holds in suspension is being replaced periodically. If you have replaced all the oil over a typical oil change interval I can't see why you'd want to replace it. Though it would make sense to replace the oil filter at a typical oil change change interval.

For an oil burner, I'm not so sure. If the oil is getting past the rings, I would hypothesize that only the oil is getting past and being burned and what has been held in suspension is being left behind and would therefore accumulate. The same might be true for oil getting past valve guides. In either case (until there is an oil analysis that showed otherwise) I'd expect that the oil and filter would need changing at some interval, and I'd start with the typical change interval.

I don't know any of what I've said above is true but that's where I'd start the discussion.

Nowadays if I had a vehicle that was leaking or burning oil at that rate I'd do something about that instead anyway. I did have an oil burner in my younger days (Ford 289 V8 with 80,000 miles) and it seemed to burn less oil when the oil was fresh. So I changed it for that reason as well. With modern oils I doubt that would be true.
This is the way it seemed to me, had one of those Celica’s 2000 1.8l burned a quart every 100 miles, I always poured in new oil of whatever I could find on sale at Walmart. That oil always looked so dirty and as black as could be. Adding a quart every 100 miles you would think the oil would look brand new.
 
Top