I would like to ask forumers here for their opinion regarding used oil analysis. how useful do you folks find it for your long term usage?

i have done one analysis and would look to doing another every say 50/60,000 kms to assess the health of my engine amongst other things.

how have other forumers found it useful for them?

 

I use oil analysis on all my vehicles. On my S2000, I did one at 15K and one at 30K miles. I think this is a good interval for an engine that seems to be running well. I have 50K now, so the current fill will get analized soon.

UOA pros:
-establishes wear trends to monitor for internal parts that may be starting to wear abnormally
-can tell you the useful life of your oil if you have a TBN and TAN performed (useful for extended intervals)
-will tell you what the viscosity of the oil is while in service, and not what it says on bottle label when it starts out
-will tell you what contaminates are in the oil (fuel, coolant/glycol, water, insolubles, soot, etc.). This can be particularly useful just before your powertrain warranty expires.

UOA cons:
-will only measure very small particles that are not trapped by the filter or collected by a magnet
-are difficult to interpret data unless you are experienced with them
-will not tell you everything about the health of your engine, but may lead you to start investigating further

Remember that trending is the most useful purpose. So using the same oil, filter, fuels and OCI is important, as well as using the same lab evrytime. If you change a variable, then you pretty much start over from scratch.

 

I agree with INDYMAC's comments. I run a UOA with each oil change. My primary reason for doing this is to make sure my engine is staying healthy with extended Oil Change Intervals. My results are pretty consistent now so I could discontinue testing, but I like the peace of mind it gives me.

Let's face it - it's comforting to know that your engine is in great shape with your maintenance schedule.

 

INDYMAC Posted on Aug 21 2009, 01:03 PM
(fixed the "e" in everytime for ya )

Anyway..
with most of this.
The fuel variable is IMO not a go-back-to-square-1.
A longer/shorter OCI will not change things much either, especially if you recalculate ppm/1000 mile or simular.
Using a different oil and or filter will change everything!
Changing oils based on single UOA is irrational (silly really).

Also important is how to take the sample: always warm up the engine, clean around the drain plug, wait 1-2 seconds while the oil is draining before taking the sample, send the sample in straight away, ect, etc, (is there much else?)

IMO:
As for the pro's: contaminants share a first place with TBN/TAN.
Followed closely by shear stability.
Wear particles per ppm is nice, a bearing that is about to fail will probably produce bigger particles and a typical UOA will not pick them up.
Having a particle count done (much more expensive) will show them.

Reading one's first UOA showing 10 ppm of iron will not tell you anything.
If the lab has a database for your type of engine they can shed some light on it being under/at/above average, but that's it.
Once you have your own series of UOA's a rise of 5 ppm iron will.... (or should) not scare you either.

A stack of UOA's on the same oil & filter used on the same engine is nice and will give you an idea of the condition of the engine and the oil used in it.
But it might still drop a valve after an overrev 10k miles ago.

 

thank you for the pointers guys! i will think about when my next uoa will be then. as i am seeking to maintain the car long term, i plan to keep all variables the same and maybe do another uoa in 20,000 miles.