Mobil1 0W20 Oil analysis reports

OOOOooo. Nice numbers.

Uhhh. What do they mean? Medical lab reports come with the "normal" values in parenthesis after each reported value.

 

TheForce: thanks for the oil analysis tracking...I also use Mobil1 in my 2005 Prius and have been curious about how long I can go between oil changes.
I do have some more interpretation questions for you, however:
1. what is significance of very high moly level (more than 3 times avg)?
2. Same question with the boron level (twice the universal avg).

thanks

 

Only surprise is the TBN is "down" to 2.7 @ ~5300 miles.
I would have expected it to have more life than that in the vaunted M1.

 

<div class='quotetop'>QUOTE(Priusaurus110 @ Jul 28 2007, 12:48 AM) [snapback]486547[/snapback]</div>

http://www.blackstone-labs.com/gasoline_di...eport_expl.html

 

It would be good to combine your UOA with maineprius947's thread on this topic in care maint and TS:

http://priuschat.com/Used-Oil-Analysis-UOA...val-t27461.html

Concerning the rapid early decay of TBN, neptune spacebears found something like exponential decay testing Mobil 1 and AMSoil in a different car. Jay Groh's results are consistent with that pattern.

 

What is TBN?

I use Amsoil 0W30 and change every 10,000 miles (6 months). I have not had a UOA done.

PA P

 

<div class='quotetop'>QUOTE(PA Prius @ Jul 29 2007, 11:32 AM) [snapback]487136[/snapback]</div>

Total Base Number

 

TBN measures the oil's remaining capacity to neutralize acids produced in fuel combustion, and slipping past the piston rings (or other access pathways to the oil). A new oil starts with TBN from about 8 to 11, depending on its additives.

According to the TBN technique Blackstone uses, a value of 2 means 'almost gone' and 1 means 'let's change oil now". But I don't know why its decay appears non-linear through time.

With synthetic oils in Prius (based on data so far) TBN is the first thing to go. Viscosity seems stable, and the engine is not usually releasing enough crud to degrade the oil's lubrication.

 

Why do you use the wrong weight oil?

 

<div class='quotetop'>QUOTE(richard schumacher @ Jul 29 2007, 11:47 PM) [snapback]487307[/snapback]</div>

5W-30 is a sort of "universal" viscosity in North America. It's part of the API/Big Oil culture to promote frequent oil changes. By having "universal" viscosity, all those qwickee loob places only have to stock one giant tank of crap oil.

Consider that a similar motor, in a Honda, requires a 5W-20. The tolerances are almost identical. At normal operating temperatures, a 0W-20 and a 5W-20 will test out almost identical. Indeed, a *stable* synthetic 0W-20 will hold up better than a conventional 5W-30 that falls apart under stress.

In the rest of the world, people usually chose a viscosity based on ambient conditions. For the same exact motor, that could mean a 15W-40.

If used oil analysis supports it, a lower viscosity usually results in LESS motor wear. There is much less "pumping" loss from using a lighter oil, the start up lubrication is much more reliable, and as a result there is a minor improvement in fuel economy. For most of the motors out there, no matter what make, a 0W-20 will provide good used oil analysis numbers

IMHO if you regularly operate in winter temps down to -40, like I do, then a synthetic 0W-30 or 0W-20 is a must.

Ironically the first place I saw a synthetic 0W-30 was at a Pep Boys in Utah. Nobody in Canada carried it, with the exception of Esso and their heavy duty version, XD-3 0W-30.

 

<div class='quotetop'>QUOTE(TheForce @ Nov 21 2007, 04:09 PM) [snapback]542616[/snapback]</div>

What are "Universal Averages []"?
Do you have a reference or virgin oil sample?

I loaded your numbers into a spreadsheet and noticed the following were up: Calcium, Zinc, Phosphorus, Molybdenum and Boron. These are typically found in oil additives and this suggests the second oil might have come from a different batch. Could it have been the 'extended' use version?

Your Silicon, Magnesium and Iron rates were lower, a very good thing. The rest of the elements were so low that we can't really draw any conclusions.

It looks like your first oil change was actually a flush. The second change shows lower rates of wear material, you've made it cleaner, and higher rates of additives, suggesting possibly a change in formulation by the vendor or a better grade, perhaps the extended use oil.

Bob Wilson

 

<div class='quotetop'>QUOTE(TheForce @ Nov 21 2007, 09:10 PM) [snapback]542758[/snapback]</div>

Don't do it for me. I am always more interested in comparing oil to a "reference sample." This gives us the additives so we can tell how they changed over time.
<div class='quotetop'>QUOTE(TheForce @ Nov 21 2007, 09:10 PM) [snapback]542758[/snapback]</div>

My references state that additive loads change by batch and this would make sense. I find it hard to believe the filter caused the additives to go up. I agree with Blackstone that the first change was a flush.

I'm attaching the Excel spreadsheet I used to look at your results. Let me suggest you download it and use it in the future to track your progress.

GOOD LUCK!
Bob Wilson

 

<div class='quotetop'>QUOTE(TheForce @ Nov 21 2007, 09:43 PM) [snapback]542768[/snapback]</div>

I take it you were able to see the graph?

It has been a while since I used OpenOffice but I think it can handle the graphs too. The trick is using a log scale on the Y axis. This let's you see the change in the very high additives as well as the much lower, orders of magnitude lower, wear material.

GOOD LUCK!
Bob Wilson