Oil Analysis

[hyuan]

Thought I would post the results of my recent oil analysis after 5000 miles.

Oil Analysis File (PDF)

Oil is no longer useful once TBN reaches 2. I was surprised by my TBN (around 8) even after 5000 miles. I may run the car to 7,500 miles like the manual states and see.

Incidentally, the oil was a dark mud when I pulled it out. It certainly looked like it should be changed.

Before everyone jumps on me as to why I am interested in longer drain intervals, I'll go ahead and answer that:

1) The oil is bad for the environment, even a little bit of prevention helps.

2) I don't like changing oil or going through the hassle (less often is better). If I enjoy maintenance, I would have bought a Ferrari.

3) Yes, it does save money. Not much, but it does.

If I perform another analysis, I will post it here. Incidentally, my car was sampled back when it had 104K miles on the clock and is a 94.'

 

[kgb_agent]

If you care anything about #3, you certainly wouldn't even CONSIDER being serious about buying a Ferrari in #2.

 

[KGP]

1) The oil is bad for the environment, even a little bit of prevention helps.

On the other hand, used motor oil can be a source of power , reducing other fossel fuel expenditures. Something the Caleeeforneean's (Ahnold talk) can use.

 

[Yellow Rose]

The oil is bad for the environment, even a little bit of prevention helps.

What are you talking about? Used oil is not disposed of by "simply dumping it on the ground".....there are stringent re-cycling laws in all fifty states!

Oil is bad for the environment? So is gasoline by way of exhaust gas pollution, so we should all park our NSXs?

 

[NetViper]

Cool! Thanks for the analysis. I guess I don't need to change my oil every 3K with Mobil one.

 

[hyuan]

Andy/KGB,

If you guys would like to discuss the merits of changing oil more frequently or less frequently, please resurrect some of the older threads that have addressed this issue.

I am merely sharing the results of my oil analysis and trying to explain why I am interested. Both of your comments seem to add little to the discussion. If you have some insight into how much longer I could go before draining it based on the test results, I'd be happy to hear it.

As for your remarks...

If I do one less oil change per year, it does indeed cost me less per year. If I do one less oil change per year, I do indeed consume less motor oil (and hence less waste). Is this significant in the grand scheme of the cosmos? No. But this is my choice and I am not here to debate that choice with you or anyone else (again start another thread).

Let's just stick to the oil analysis shall we?

 

[Dash Rip Rock]

Hyuan, thank you for posting the report. How would characterize your driving style. That would have an effect the oil degradation.

 

[Briank]

Oil Analysis quantifies what is really happening. Even in light of hard measurements there is no end to subjective observations and antidotal reasons for short oil change intervals. The bottom line is modern fuel injected, computer controlled engines just don't mess up the oil like the in the past.

 

[hyuan]

Hyuan, thank you for posting the report. How would characterize your driving style. That would have an effect the oil degradation.

Miles wise I am 90% freeway, 10% local. Time wise, I would say its about 60% freeway, 40% local. My drives are mostly straightline drives for my commute; cruising between 60-80. I may downshift 2-3 times per trip for passing purposes and red line on freeway merges in 2nd and row through the rest once I am at speed. Once or twice a month, I may take it to the twisties for some fun in the hills. On open roads, I try to drive under 80.

My car also accrues about 16K-17K miles per year.

What I thought was interesting was that the color of the oil was not an indicator that it should be changed.

Dash is right in that driving habits do impact oil degradation... and my driving is not aggressive relative to others. It is however driven everyday, all year long, rain or shine....

 

[sjs]

... Oil is no longer useful once TBN reaches 2. I was surprised by my TBN (around 8) even after 5000 miles...

I post this frequently, but I'll do so again since there is always someone who hasn't seen it.

http://neptune.spacebears.com/cars/stories/oil-life.html