Used Oil Analysis (UOA) or Analyses and Extended Oil Change Interval

[dcoyne78]

[attachmentid=8679]I wanted to create a thread where oil analyses could be found easily. I am attaching a spreadsheet with some known analyses. One thing I have noticed is that some of the TBNs are much higher than others at similar mileage with the same oil, this may be due to many factors, but a simple explanation may be that different labs use different methods to determine TBN. I know that during the synthetic Oil Life Study that Blackstone changed methods and the TBN went to lower numbers for the same sample. If people whose data are in the spreadsheet attached could let me know the lab they used and the date of their analyses I could add them to the attached spreadsheet (or you can put them in yourself if you don't mind.) I wanted to recognize Tochatihu (DAS) for putting the spreadsheet together. I may re sort the database to show how things look as the oil change interval(oci) is increased, and then sort on iron and aluminum. Do we know what the average miles on oil is for the Blackstone universal averages? Thanks.

Dennis

Edited to correct who created the spreadsheet and changed spreadsheet with updates for jayman's lab.
Update on spreadsheet 1/4/2007, added sub3marathon UOA
Another update 1/10/07 and some corrections let me know if I've made mistakes on your UOA. Thanks.
Update 1/22/07 added Scott C 's analyses
Update 2/24/2007 added my analysis
Update 6/7/2007 added two analyses 10000 miles and 12000 miles

[jayman]

I have my used oil tested by Caterpillar Toremont Labs. Asides from an early high Na level, the Prius is very easy on Mobil 1

I also would like to see more results of using dealer or cheap 5W-30 to establish baselines. I should contact Duffy's Taxi in Winnipeg, at last count they were operating 45 Prius taxi cabs.

[dcoyne78]

' date='Dec 15 2006, 07:40 PM' post='362977']
I have my used oil tested by Caterpillar Toremont Labs. Asides from an early high Na level, the Prius is very easy on Mobil 1

I also would like to see more results of using dealer or cheap 5W-30 to establish baselines. I should contact Duffy's Taxi in Winnipeg, at last count they were operating 45 Prius taxi cabs.
[/b]

Thanks Jayman. I agree that it would be nice to see a few UOAs from dino, from what I have seen over at bobisttheoilguy (aka bitog) if someone is going to stick with a 5000 mi oci to maintain their warranty then synthetic oil is a waste of money. I didn't realize this until I had 50K on my car, but I might have used the Mobil 1 anyway as cheap insurance and maybe for a little better fuel economy. For a lot of people the extra $16 per oil change is worth it for peace of mind.

[jayman]

<div class='quotetop'>QUOTE(maineprius947 @ Dec 16 2006, 02:00 PM) [snapback]363149[/snapback]</div>

if someone is going to stick with a 5000 mi oci to maintain their warranty then synthetic oil is a waste of money.[/b]

I guess that would depend on the operating conditions. In "normal" conditions of temperatures not lower than -20 C or hotter than +35 C, you are entirely correct.

Temperatures to -40 C, the cold flow properties alone make a synthetic very desirable. This is true of a 0W-30 or especially a 0W-20. I have noted about an average 5-10% better city fuel economy running 0W-20 instead of 0W-30 in winter, especially in temps colder than -25 C. In temps of "only" -15 C or warmer, the difference isn't noticeable.

In January once I'm back from my vacation I'll post my UOA if you wish.

[dcoyne78]

<div class='quotetop'>QUOTE(jayman @ Dec 19 2006, 06:20 PM) [snapback]364354[/snapback]</div>

I guess that would depend on the operating conditions. In "normal" conditions of temperatures not lower than -20 C or hotter than +35 C, you are entirely correct.

Temperatures to -40 C, the cold flow properties alone make a synthetic very desirable. This is true of a 0W-30 or especially a 0W-20. I have noted about an average 5-10% better city fuel economy running 0W-20 instead of 0W-30 in winter, especially in temps colder than -25 C. In temps of "only" -15 C or warmer, the difference isn't noticeable.

In January once I'm back from my vacation I'll post my UOA if you wish.
[/b]

Thanks Jayman. You are definitely right about the dino in extreme temps, especially on the cold side. I don't see the low temps that you do. It would be great to see your UOA.

Dennis

[dcoyne78]

I just added another oil analysis to the spreadsheet, results looked good after 5K, TBN down to 2.9, I will resample at 7.5K. No makeup oil so far, Mobil 1 Oil Filter, OEM Air filter changed just before last oil change.
Oil in service on 9/26/06

Blackstone Labs Oil Analyses for 2004 Prius oil in service 9/26/06
Oil Type Mobil 1 0W20 SM
Date 12/23/2006

Eng mi 55358
Oil Mi 4903
Al 3
Cr 0
Fe 5
Cu 1
Pb 0
Sn 0
Mo 94
Ni 0
Mn 0
Ag 0
Ti 0
K 0
B 47
Si 12
Na 5
Ca 2273
Mg 11
P 631
Zn 739
Ba 0
Visc 53.9
Flash 365
Fuel % <0.5
Antifr % 0
H20 % 0
Insol % 0.4
TBN 2.9

[jayman]

<div class='quotetop'>QUOTE(maineprius947 @ Jan 4 2007, 01:28 PM) [snapback]370780[/snapback]</div>

after 5K, TBN down to 2.9,[/b]

That doesn't sound right, the TBN going to 2.9 after only 5,000 miles. At 10,000 miles the lowest I've seen so far has been around 4.9. Or does my testing lab and yours run different TBN measurements, to further confuse the situation??

[dcoyne78]

<div class='quotetop'>QUOTE(jayman @ Jan 7 2007, 07:13 PM) [snapback]372236[/snapback]</div>

That doesn't sound right, the TBN going to 2.9 after only 5,000 miles. At 10,000 miles the lowest I've seen so far has been around 4.9. Or does my testing lab and yours run different TBN measurements, to further confuse the situation??
[/b]

I think our labs use different tests to determine TBN, I noticed that some in the spreadsheet were much higher than others which is why I asked people to give me their Lab info. If you look at the results from DAS who I think (could you confirm this DAS?) uses Blackstone Labs, his TBN tends to be lower than yours at similar mileage and using the same oil. If you have looked at the synthetic oil life study from a few years ago (which also used Blackstone Labs) the TBN test method got changed in the middle of the Mobil 1 part of the study and the results were posted for both old and new TBN from 12000 to 18000 miles. Based on that study one method gives a TBN about 2 times the other, my guess is that your lab uses the first method and Blackstone uses the second method (there may be several different tests, I haven't researched it.) So as usual, you hit the nail on the head, I think the confusion is different test methods. It would be nice if there was a single test that all the labs used. According to your lab at what TBN level would the oil be "used up"? At Blackstone 1.0 is considered too low, but the people over at bitog like to see TBN at 2.0 or more.

Dennis

[jayman]

<div class='quotetop'>QUOTE(maineprius947 @ Jan 9 2007, 11:33 AM) [snapback]373035[/snapback]</div>

It would be nice if there was a single test that all the labs used. According to your lab at what TBN level would the oil be "used up"? At Blackstone 1.0 is considered too low, but the people over at bitog like to see TBN at 2.0 or more.
[/b]

Ah, that explains that. My testing lab considers TBN<3.5 essentially used up. There should be one standard, this tends to really confuse the novice Priuschat member

[dcoyne78]

Agreed. For those who look at the spreadsheet and are new to used oil analysis (UOA). Note that there are at least 2 ways to measure TBN (total base number) one gives numbers that range from 3.5 to 8.0 for oil used between 5000 to 13000 miles and the other ranges from 1.5 to 3.5. Higher numbers are better and unused oil starts at either 10 or 15 depending on the oil and method used to measure TBN. More info can be found at Bobistheoilguy, but this might be TMI for most people.

Dennis