If you have a TP bypass oil filter and change it every 3k miles, how effective is that new quart of oil at rebuilding the additives?
How effective
- Thread starter Louie's gone fishing
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Considering that you are replacing 20-25% of the oil that is there, I'd have to guess that it is pretty effective but that is just opinion. Has anyone done TBN analysis to find out?
I put about 1 and a half quarts of top-up in a 6 quart sump during a 10k OCI with one TP change that resulted in a used oil analysis with a TBN of 2.something (as I recall) running Mobil 1 Extended Performance.
Next run if nothing changes significantly, we are set to do 15k, w/2 TP changes and probably use 2 additional quarts total. This is on a Chrysler 2.7 with a Motorguard.
Do I have the record for most acronyms in a single sentence here yet?
Next run if nothing changes significantly, we are set to do 15k, w/2 TP changes and probably use 2 additional quarts total. This is on a Chrysler 2.7 with a Motorguard.
Do I have the record for most acronyms in a single sentence here yet?
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To figure your teminal condition of the oil ..you have to go through the entire sump. That's assuming that you add one quart per filter change. Whatever mileage figure you use for changing the filter ..multiply that times the sump quarts and that's where you're at the oldest it will be.
For a 6 quart sump, assuming 1 quart and 3k per tp change, would mean that 18k would be the oldest the sump can get. Every quart added from that point on will appear the same to the sump. That is, you'll operate in a narrow 3k range of additives and TBN.
For a 6 quart sump, assuming 1 quart and 3k per tp change, would mean that 18k would be the oldest the sump can get. Every quart added from that point on will appear the same to the sump. That is, you'll operate in a narrow 3k range of additives and TBN.
So if you have a 6 quart sump, change the oil every 5k miles and change the tp filter every 2.5k miles, you should have really clean oil.
2.5 x 6 = 15 divided by one oil change makes it 7k, or something like that.
2.5 x 6 = 15 divided by one oil change makes it 7k, or something like that.
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Louie ..I'm not sure what you're figuring
You've gone 2.5k on 6 quarts ...exchanged one ....then went another 2.5k ...then apparently dumped the whole sump
Yes, you should have clean oil. It's only been in service 5k with two make up quarts for tp changes.
Now if you just change tp every 2.5k and it's a 6 quart total sump ....it will take about 15k to get to the "perpetual sump" status.
It would, probably, resemble a 6 quart sump that was at 7.5k (albeit very clean 7.5k).
Yes, you should have clean oil. It's only been in service 5k with two make up quarts for tp changes.
Now if you just change tp every 2.5k and it's a 6 quart total sump ....it will take about 15k to get to the "perpetual sump" status.
It would, probably, resemble a 6 quart sump that was at 7.5k (albeit very clean 7.5k).
I think Louie's interest in bypass filter is reflected in his post about his Falcon. 32 years of 2k tp changes, no oil change. It appears that the plan to change the tp and not the oil will work if you can figure out what to do about the ff filter. In his case he bypassed it, never used one. I think the Falcon was 4 qts plust about 1 qt for the filter. So was his oil like an 8k oci?
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I see. I just didn't quite integrate what he posted. Then again ...I hadn't taken my meds yet
Of the original 5 quarts involved - removing 1 quart (20%) at each tp change:
Start 5 quarts (100%)
1st change: 80% left
2nd change: 64% left
3rd change: 51.2% left
4th change: 41% left
5th change: 32.8%
6th change: 26.2% left
7th change: 21% left
9th change: 13.4% left
10th change: 10.73%
Every quart that you add in % that it represents of the composite:
20% (0-3k)
16%
12.5%
10.24%
8.192%
6.55%
5.24%
4.19%
We then (I THINK) we see this:
100%
80/20 (more older oil)
64/16/20 (more older oil)
51/12.5/16/20 (more older oil)
41/10.2/12.5/16/20 (more older oil)
33/8.2/10.2/12.5/16/20 (more older oil)
26/6.5/8.2/10.2/12.5/16/20 (averages more newer oil then older oil)
21/5.2/6.5/8.2/10.2/12.5/16/20 ( here's where the oldest oil is about equal to the make up quart)
13.4/4.2/5.2/6.5/8.2/10.2/12.5/16/20
10.7/3.3/4.2/5.2/6.5/8.2/10.2/12.5/16/20
8.5/2.6/3.3/4.2/5.2/6.4/8.2/10.2/12.5/16/20
I'm sure that there's a MUCH easier way to figure this out ..but I think that it could be as simple as the sump times the make up rate ..in this case ..15k-18k ..to see where you, more or less, bottom out. That should make the mean mileage about 7.5-8.5k. Keep in mind that this is at a very fine level of filtration.
The bigger the sump ..the longer it takes you to bottom out
Let's take a 2 quart sump (3 total with tp filter)
100%
66.7/33.3
44.5/22.2/33.3
29.7/14.8/22.2/33.3
and so on
This is totally exclusive of what you'll see in stuff like TBN retention due to the service it sees. Suppose you live in AZ with virtually zero humidity? You may never deplete the buffers in the original sump due to moisture. I think in that case, you'll still "bottom out" at the same mileage ..but the number will just be higher.
I'm totally open to other points of view on this ..since I can surely be totally wrong here.
[ July 20, 2006, 11:55 AM: Message edited by: Gary Allan ]
I thinks so. Let's see how many changes it takes to get to where the oldest oil in the sump is equal to the make up oil. This may make me rethink my numbers a little.
Of the original 5 quarts involved - removing 1 quart (20%) at each tp change:
Start 5 quarts (100%)
1st change: 80% left
2nd change: 64% left
3rd change: 51.2% left
4th change: 41% left
5th change: 32.8%
6th change: 26.2% left
7th change: 21% left
9th change: 13.4% left
10th change: 10.73%
Every quart that you add in % that it represents of the composite:
20% (0-3k)
16%
12.5%
10.24%
8.192%
6.55%
5.24%
4.19%
We then (I THINK) we see this:
100%
80/20 (more older oil)
64/16/20 (more older oil)
51/12.5/16/20 (more older oil)
41/10.2/12.5/16/20 (more older oil)
33/8.2/10.2/12.5/16/20 (more older oil)
26/6.5/8.2/10.2/12.5/16/20 (averages more newer oil then older oil)
21/5.2/6.5/8.2/10.2/12.5/16/20 ( here's where the oldest oil is about equal to the make up quart)
13.4/4.2/5.2/6.5/8.2/10.2/12.5/16/20
10.7/3.3/4.2/5.2/6.5/8.2/10.2/12.5/16/20
8.5/2.6/3.3/4.2/5.2/6.4/8.2/10.2/12.5/16/20
I'm sure that there's a MUCH easier way to figure this out ..but I think that it could be as simple as the sump times the make up rate ..in this case ..15k-18k ..to see where you, more or less, bottom out. That should make the mean mileage about 7.5-8.5k. Keep in mind that this is at a very fine level of filtration.
The bigger the sump ..the longer it takes you to bottom out
Let's take a 2 quart sump (3 total with tp filter)
100%
66.7/33.3
44.5/22.2/33.3
29.7/14.8/22.2/33.3
and so on
This is totally exclusive of what you'll see in stuff like TBN retention due to the service it sees. Suppose you live in AZ with virtually zero humidity? You may never deplete the buffers in the original sump due to moisture. I think in that case, you'll still "bottom out" at the same mileage ..but the number will just be higher.
I'm totally open to other points of view on this ..since I can surely be totally wrong here.
[ July 20, 2006, 11:55 AM: Message edited by: Gary Allan ]
I quick check, while doing such a scheme could be the use of a TBN check. I think you can buy a kit to do those, have you ever used one?
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Who you talin' to, Louie? Bypass filter or used oil analysis
I'd say that TBN would be a fair indicator. A particle count surely shows the superior filtration of a TP filter ...with distinction. There is no two ways about it, TP is the best cheapest media that there is. You would have to spend probably 100:1 in spin-on filtration to match it.
I have several bypass filters ..none are installed currently and only one had a used oil analysis (without particle count). I've never put a tp bypass filter in service.
In my long post, I should have used the term "original" oil in place of "older". As you can see, it takes a few miles to reduce it to "huh?".
I'd say that TBN would be a fair indicator. A particle count surely shows the superior filtration of a TP filter ...with distinction. There is no two ways about it, TP is the best cheapest media that there is. You would have to spend probably 100:1 in spin-on filtration to match it.
I have several bypass filters ..none are installed currently and only one had a used oil analysis (without particle count). I've never put a tp bypass filter in service.
In my long post, I should have used the term "original" oil in place of "older". As you can see, it takes a few miles to reduce it to "huh?".
What about that Amsoil spin on bypass filter?
I remember seeing someone posted in another thread that the TBN of his UOA actually increased with the subsequent additions of make-up oil with a bypass filter.
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That surely could occur. As you see in the above table, the original sump is the majority of the oil in there for a fairly long time. At least for 15k/15m
I do not understand the logic here. If the make up oil provides more than enough TBN to make up the loss each time, why would TBN eventually run out in the end? There should not be the need to change oil with a TP bypass filter as long as the TP is changed with make up oil, right?
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You perhaps misunderstand me. Look at the above table that I posted. Everytime you take a quart out with a filter change, you take out 20% of everything ..not just the old oil. So 20% of all newer oils are also removed.
At 12k/12m you still have 41% of the original sump.
Here's what a new quart looks like in the composit sump as the mileage advances
20% (0-3k)
16%
12.5%
10.24%
8.192%
6.55%
5.24%
4.19%
Here's where you may find a TBN increase:
21/5.2/6.5/8.2/10.2/12.5/16/20 ( here's where the oldest oil is about equal to the make up quart)
The make up oil is at full TBN level ..and the near equal amount of the original sump is about 21k old ..and still in there. That 21k old dino is surely spent as far as its contribution to the TBN level. Beyond here the TBN may climb a bit more as the original sump begins to resemble the % of added quarts as they're partially removed in the process.
At 12k/12m you still have 41% of the original sump.
Here's what a new quart looks like in the composit sump as the mileage advances
20% (0-3k)
16%
12.5%
10.24%
8.192%
6.55%
5.24%
4.19%
Here's where you may find a TBN increase:
21/5.2/6.5/8.2/10.2/12.5/16/20 ( here's where the oldest oil is about equal to the make up quart)
The make up oil is at full TBN level ..and the near equal amount of the original sump is about 21k old ..and still in there. That 21k old dino is surely spent as far as its contribution to the TBN level. Beyond here the TBN may climb a bit more as the original sump begins to resemble the % of added quarts as they're partially removed in the process.
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