I Don't Change My Oil - Test Results

[jsinton]

Originally Posted By: The_Eric
Originally Posted By: jsinton
Originally Posted By: gathermewool
How much oil is replenished during a filter change?

If you're not generating much in the way of contaminants and your goal is resource conservation, then wouldn't using a better filter for twice the interval or longer make more sense?

Many of us who do change our oil every 7-10k miles leave the filter for up to twice that that long (for my Honda - 6k interval for the Subie). In fact, if you change your oil filter every 3k miles you're tossing 5 filters away for every one I toss.


Yeah, I don't believe keeping a filter on for a long time is such a great idea. If you've ever owned a vacuum cleaner, a fish tank, changed a air con filter, etc. you can see the logic. It's important to keep oil pressure high. An oil filter might still work after 12k, but for sure you've lost oil pressure. So I don't believe the kool-aid about "high mileage" oil filters. You lose pressure, it's as simple as that.


You've taken a reasonably sound approach to this, but your knowledge is lacking when it comes to oil filters and TBN.

Excess TBN's floating around????

Also, running an oil filter longer will result in greater efficiency and lower solids- this I'm sure you know. What you seem to be missing is that the same amount of oil WILL pass through the filter, no matter it's state of loading. This is because the type of oil pump autos use is called positive displacement. They WILL push a set amount of oil through a given restriction, or restrictions (filter, oil galleries) no matter what. Your concern of LOWER oil pressure is unfounded. In fact, the greater the restriction, the GREATER the pressure (pressure is a measure of restriction). If a filter becomes so loaded that it can no longer filter or pass oil without self destructing, then it or engine (depending on design) will by-pass the filter media. This is set to happen on PSID (pressure differential or delta). Typically around 7-10 lbs. Member Jim Allen has some excellent info on this from an extended data logging session he did.

Ideally to conserve time and resources, you'd figure out how to run a filter to the point of by-pass, at which time, you'd replace it and top off the oil. By keeping unneeded filter changes to a minimum, you're also keeping wastes and energy consumption associated with manufacturing (from mining of raw ore to finished products) down.

Now the reality is that while your efforts are worthy of applause, they will not have a measurable impact unless a FAR greater percentage of the motoring public joins you.


Bypass filters are great, if you're lazy and your filter is clogged. But who wants unfiltered oil flowing through their engine? Look at it this way: If you had a vacuum cleaner with a bypass filter, would you want it to clean your house with it? I sure wouldn't. It would be blowing all that dust that I just tried to clean, would it not? And I don't believe the theory about oil pressure remaining the same whether the filter is clogged or not. Why? Just my experience with analog oil pressure gauges. Oil pressure is highest right after I change the filter. It's as simple as that. And what is wrong with too much TBNs? Well nothing so long as your motor is very clean. But if you try to dump oil with a lot of TBNs into an old motor with gunk, it could ruin your engine by loosening up gunk and clogging the lifters, so if you have an old motor with dino oil, stick with the dino, because synthetic has too much TBNs.

 

[jsinton]

Originally Posted By: CELICA_XX
I read somewhere that in a situation like this, the "lighter" molecules in the oil will burn off first, leaving behind a thicker mixture in the sump.

So even with an oil burner, you still need to do a drain & fill occasionally.

Is there any truth to this?


I don't know. It's an interesting theory, but I'm not going to test for sump gunk accumulation right now. I'm trying to get 100k out of my oil.

 

[Shannow]

That theory seems to be based on the view that some people have that oil "boils off" at sump temperatures and the light stuff flows through the PCV, thickening the sump contents.

Was reasonably popular here a little while ago.

 

[DuckRyder]

That engine is pretty clean at least on the top (save for all the blue RTV)...

I'm intrigued, I applaud your fortitude in giving this a try.

A couple of points.

I don't think this would work without the 1qt/4000mi of make up oil.
I wonder how use of resources with the frequent filter changes compares to say a 10,000OCI/20,000FCI.

 

[demarpaint]

Nice write up. I'd bet a car that doesn't use any oil could achieve similar results by changing the filter and extracting enough oil to equal a qt. Then replacing the filter and adding a qt. of fresh oil.

 

[virginoil]

I didn't see anywhere in the thread how much the OP tops up with over a year of driving.

It would be useful if the OP confirms how much oil is added to the vehicle over 1 years driving and the mileage covered in that period.

Including how often the oil filter is changed is it by mileage or by time period.

 

[Quattro Pete]

Originally Posted By: deven
Would the results be the same if I never had to add oil?

I doubt it. The OP added about 13 quarts of new oil throughout the course of these 51k miles which helped replenish the additives.

 

[virginoil]

Originally Posted By: Quattro Pete
Originally Posted By: deven
Would the results be the same if I never had to add oil?

I doubt it. The OP added about 13 quarts of new oil throughout the course of these 51k miles which helped replenish the additives.


Assuming you need 4 quarts per oil change then it is like one (1) OCI per 17000 miles over the 3 year period. I would not recommend this practice continue at that oil change rate.

One full OCI period ie 4 litres per 10000 miles would be better, if the OP continues the practice then he should change the oil filter more often to increase the amount of oil that will need to be added until the 4L per 10000 miles OCI equivalent is achieved IMO.

 

[The_Eric]

Originally Posted By: jsinton
Bypass filters are great, if you're lazy and your filter is clogged. But who wants unfiltered oil flowing through their engine? Look at it this way: If you had a vacuum cleaner with a bypass filter, would you want it to clean your house with it? I sure wouldn't. It would be blowing all that dust that I just tried to clean, would it not? And I don't believe the theory about oil pressure remaining the same whether the filter is clogged or not. Why? Just my experience with analog oil pressure gauges. Oil pressure is highest right after I change the filter. It's as simple as that. And what is wrong with too much TBNs? Well nothing so long as your motor is very clean. But if you try to dump oil with a lot of TBNs into an old motor with gunk, it could ruin your engine by loosening up gunk and clogging the lifters, so if you have an old motor with dino oil, stick with the dino, because synthetic has too much TBNs.



We're not talking about by-pass filters here (a whole other type of filter). We're talking full flow filters that have the capability of by-passing the filter media in the event that it becomes to restrictive. Comparing it to a dirty vacuum is a bad analogy.

On your experiences with higher oil pressure after a filter change, are you sure it's not just from cooler oil? You know, shut it down, then let the engine cool to do your service work, then return it to service and you start paying attention to the oil pressure... It'll be higher then, due to the lower oil temps- which can take a significant amount of time to come back up. You mentioned lots of short trips- engine run time/load will impact an oil's temp and can vary wildly. You need to come back with lots of solid data showing us exactly what is going on here, as your routine won't be routine enough to draw any solid conclusions.

Assuming the oil pressure sender is downstream of the filter and the gauge is accurate, 3000 miles isn't enough time to load a filter to the point where it will you will see it on the gauge (unless there is an incredible amount of junk in the engine and you're using harsh solvents. Like I said, a filter will typically by-pass at around 7-10 psid, so at most you'd see maybe a 10lb drop, but only if you ran it for ~15 to 20k miles... Maybe even more.

As for TBN(s), you're confused on what it actually is/does. TBN is the measure of an oil's reserve alkalinity, which gives it it's ability to fight the formation of acid (combustion by-product) formation/build up. The additives that contribute to an oil's TBN contribute as "cleaners", but so do the base oil and some of the other additives. None are so aggressive that a fresh change of oil will knock untold amounts of "crud" loose and plug up the oil pump pick up tube. It doesn't matter the brand, what they say in the advertisements or what you read here on this board. Speaking of crud, if those are indeed your pictures, then there won't be enough "crud" to knock loose and plug anything up.

Again, I think this is neat, but I'm getting the impression that you're somewhat misinformed and lacking some critical data to back your assertions.

 

[Kuato]

Originally Posted By: jsinton
Originally Posted By: Kuato
This is all quite interesting. I would be interested to see what the TBN is at 100k....or currently for that matter.

I believe there's WAAAAAY to much emphasis placed on TBN level and not enough placed on filtration. Too much TBNs have an effect of loosening up gunk and trashing motors. I see people try to switch to synthetic oil on an old motor, only to have the TBNs loosen up the gunk and kill the lifters.


True! Going by TBN alone isn't wise. Perhaps I should have said I would like to see TBN to complete the picture, or to compare against TAN, for example.

 

[A_Harman]

This is one of the more interesting ongoing "experiments" on BITOG. The last time the subject came up, I suggested that he use Fram High Mileage oil filters, which have a gel in them that gradually releases additive to neutralize acids. I still think that would be a good addition to this experiment if he continues to do UOA's.

Also, TBN should be measured as well as TAN in the oil samples.

For the curious, here is the previous thread on the subject:
http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3339795/1

 

[FloatingBrick]

Quote:
We're not talking about by-pass filters here (a whole other type of filter). We're talking full flow filters that have the capability of by-passing the filter media in the event that it becomes to restrictive. Comparing it to a dirty vacuum is a bad analogy.


The Eric - Please don't don't bring reason and facts to the table.

 

[JustinH]

Nice experiment, but why not spend 20 bucks once a year to get the oil changed?

 

[Nickdfresh]

Whatever you save in oil changes, you're spending on UOA's and reduced fuel economy...

 

[jsinton]

Because for me to maintain the oil as clean looking, it would require almost four oil changes a year, which would run more like $80 in my case. As it is, I probably spend less than $28 per year.

 

[jsinton]

Originally Posted By: Nickdfresh
Whatever you save in oil changes, you're spending on UOA's and reduced fuel economy...
No evidence of that. My oil tests reveal the oil is clean, and I routinely get mpg %30 better than my peer autos.

 

[TiredTrucker]

I get it, when it comes to changing my semi truck oil several times a year, at 10 gallons and two Donaldson filter each time, that UOA's to see if I can stretch the drains out and save $1000 or more a year, but for my pickup that takes 6 qts and a small filter? Not worth the trouble. The OLM down to 10% works just fine for me. One looking from the outside would begin to gather from some of these extended drain ideas that motor oil is selling for $100 a quart and you have to reserve what you need 6 months in advance.

 

[CATERHAM]

Originally Posted By: The_Eric

Assuming the oil pressure sender is downstream of the filter and the gauge is accurate, 3000 miles isn't enough time to load a filter to the point where it will you will see it on the gauge (unless there is an incredible amount of junk in the engine and you're using harsh solvents. Like I said, a filter will typically by-pass at around 7-10 psid, so at most you'd see maybe a 10lb drop, but only if you ran it for ~15 to 20k miles... Maybe even more.

That's been my experience.
Years ago I tried the Restore Engine Treatment in an engine with
low compression. The can contains solid material suspended in oil. The product actually works but it doesn't last long.
One side affect of using the stuff was that it would clog the oil filter with an immediate 10 psi drop in oil pressure. Upon replacing the filter the normal OP would return.

So I agree the OP is changing the oil filter way too frequently.
If the objective is to minimize maintenance he should wait for the filter to actually clog and that could take 20k or even much longer to happen if he uses a long drain filter.

 

[A_Harman]

Originally Posted By: CATERHAM
So I agree the OP is changing the oil filter way too frequently.
If the objective is to minimize maintenance he should wait for the filter to actually clog and that could take 20k or even much longer to happen if he uses a long drain filter.


+2. He could probably double his filter change interval and still use base-level filters. This would change the TBN replenishment rate, though, because he's probably adding 1/2-qt of fresh oil with every filter change.

 

[JustinH]

Originally Posted By: jsinton
Because for me to maintain the oil as clean looking, it would require almost four oil changes a year, which would run more like $80 in my case. As it is, I probably spend less than $28 per year.


What is your yearly mileage?

How much is the engine in this vehicle?

We get tons of firestone and goodyear oil change coupon deals, for 19-20 dollars every time. How much is the filter you buy, and the quart of oil to top it off?

Are you really saving anything?