Oil analysis, should I bother? Engine consumes oil.

[Quick_lude]

My 2.2l VTEC Prelude engine consumes oil regularly, more if I VTEC a lot.

So for example, during my last 8500km with GC 0w30 so far I topped up with 2.5L. I'll probably change the oil at about 10-12000 km, should I bother with analysis? By then I'll probably have almost 4L of top up oil in there, which would skew the results a lot..

[ January 28, 2004, 02:23 PM: Message edited by: Quick_lude ]

 

[Al]

Well you can allow for that in the analysis. If you used 4 quarts and the pan holds 4, you can figure your oil wear particles should be around half of what they would be without makeup and the oil would be expected to be proportionally higher. Plus you would be able to check for silicon, antifreeze, insolubles, and dilution. This could give you a snapshot of vehicle efficiency/health.

 

[Quick_lude]

but since I'm consuming and replenishing, wouldn't those numbers be affected too?
For example, I'm at 2000km with 5L of oil and 12 ppm of iron. During the next 2000km the engine consumes 1L of oil. If I sampled at that point would the iron level still be 12, just like when I had 5L of oil in there? What about after I top up with 1L of fresh oil. Would the Iron level still be 12? This question of course is valid for any other ppm measurement..
I already know that TBN and viscosity would be affected..