This might seem a damn fool question to some of you, and I could probably google the answer.
But a discussion would be more fun - this is after all a forum.

I don't have an oil leak AFAIK, there's never oil where I park at home or work, but my oil has gone down by an X and a half on the dipstick.

Is it just burning to vapour and escaping somehow?
Is it being broken down from a thick substance to a thinner substance with less volume?
Is some oil-pixie stealing it while I sleep? (some evil cousin of the beer monkey perhaps?)

Enlighten me please.

 

2 reasons it seems.

1) it breaks down
2) it gets past the seals

https://www.s2ki.com/forums/index.php?showtopic=526472 Si2k works for Castrol so has a pretty good idea of what goes on.

 

Older models use more oil than later models 02+.

Its normal.

 

I think the question was more one of "where/how does the oil disappear/to"?

 

Past the rings into the cylinder head and gets burnt off during combustion. This is likely if you VTEC alot.

Oil vapour is 'pushed' out via the PCV and back into the head as part of the intake cycle, so it gets burnt once more during combustion.

 

Thanks loftust,

What's a PCV? (guessing V = valve)?

 

Ventilation

 

PCV = Positive Crankcase Ventilation, which is controlled by a valve.

 

PCV system does two different things.
1. It scavenges blowby gas (combustion gas that gets past the rings) and reburns it preventing the nasties in the gas being emitted.
2. By reburning the gas it smothers and slows the process slightly at moderate throttle loads. This means less in the way of nasties being produced by the combustion process

 

Thanks gents