UOA: Pennzoil 5W-40 5K OCI, 2011 BMW 328i N51 95K miles

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Hello again:

The latest UOA for our E90 BMW. Low flashpoint compared to the others, but no fuel dilution like the others. Why do you think?

This is my first UOA with Pennzoil 5W-40. I started using it 15K miles ago (three OCIs).

31K sample = German Castrol 0W-30 (the made in Germany version, not Belgium)
47K sample = Liqui Moly Leichtlauf 5W-40 (this sample had just 128 miles on it!)
81K sample = BMW TPT 5W-30 (the LL-01 version)
95K sample = Pennzoil 5W-40 (A3/B4, LL-01, etc)

Enjoy,

Scott
 

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A reduction in flashpoint is fuel, even if they don't flag it as fuel. Blackstone's fuel percentage is inferred not measured via GC, so I expect you'd get a different figure if this sample was sent to a lab that used GC.
 
A reduction in flashpoint is fuel, even if they don't flag it as fuel. Blackstone's fuel percentage is inferred not measured via GC, so I expect you'd get a different figure if this sample was sent to a lab that used GC.
I'm curious why this sample has a low flash point compared to the others. I have a trend line with the car. Are you saying that even if I had fuel dilution issues on the earlier samples, BS would not have detected it via dilution %? And that the BS results can only suggest fuel dilution based on the flash point?

But this is my first UOA of this oil. That's another variable. The car seems to run fine, just like it always has. No codes and no reason to think something is wrong. Starts and runs great. I put in new plugs and coils 15K miles ago. The car is very well maintained.

It's a mystery for now. I'm going to track gas mileage for awhile. Maybe that will provide some insight.

Scott
 
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I'm curious why this sample has a low flash point compared to the others. This is my first UOA of this oil. That's a variable. Does this oil behave like this? The car seems to run fine, just like it always has. No codes and no reason to think something is wrong. Starts and runs great.

It's a mystery for now. I'm going to track gas mileage for awhile. Maybe that will provide some insight.

Scott

Did you do a bit more short tripping this OCI? That's all it takes.
 
That's possible, but if I did it wasn't enough for me to remember! :) I seldom short trip that car. That said, I have alway been conscious of warming up oil before revving, getting up to full operating temp to control crankcase condensation, etc. I always drive the car 10 or 12 miles before changing.

Thanks for the comment,

Scott
 
You know, another thing. In UOAs where there’s fuel dilution there‘s significant viscosity loss. This appears to be the case in this OCI. It does look like fuel dilution as OVERKILL suggested. I do not recall short tripping this car. That’s not how this car is used.

I’m going to track fuel mileage and monitor coolant temps.

Scott
 
Nice car! My 2009 328i looks identical (same color) and also an N51. What wheels are those? I just have some 17" style 285's for summer and some 16" wheels I use with snow tires. I've done a UOA on mine both with Castrol 0w40 and Liqui-moly 5w40.
 
Nice car! My 2009 328i looks identical (same color) and also an N51. What wheels are those? I just have some 17" style 285's for summer and some 16" wheels I use with snow tires. I've done a UOA on mine both with Castrol 0w40 and Liqui-moly 5w40.
Thanks, jeep man. It's an M-Sport model. The wheels are BMW Style 225M; 19x8 front, 19x9 rear.

Scott
 
That's possible, but if I did it wasn't enough for me to remember! :) I seldom short trip that car. That said, I have alway been conscious of warming up oil before revving, getting up to full operating temp to control crankcase condensation, etc. I always drive the car 10 or 12 miles before changing.

Thanks for the comment,

Scott
Could be, but we are talking PP Euro SN+, right? That is pretty thin W40 at 12.8. Yes there is loss of viscosity, but it is bit strange. I think if you had TBN numbers it would tell us more.
 
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