BL> I've been tempted to do this myself, but I usually chicken out and change
BL> the oil every 6 months. I was told by a chemical engineer who reprocessed
BL> sump oil that the filtered oil is actually better than the original. The
BL> short chains and impurities break down and get filtered out.

KR> the only problem is the build up of corrosive condensates if you only
KR> do short/slow trips. if you keep a motor running at it's optimum all the
KR> time, then the oil can last a very long time. i read about the pommy police
KR> motorway patrol cars, running 160000km in a year with, i think just 1 oil
KR> change, but they were running at about 100kph 23 hours a day, never got col

BL> This is true. Taxis get the same. But how does
BL> replacing oil frequently reduce the corrosion?

It had additives designed to neutralise those corrosive condensates.
Eventually you use those up, and new oil has a new supply of those.

BL> That would only work if you changed it every time you used it!

Nope, coz the additives neutralise the corrosive condensates.
Modern oils are a hell of a long way from just oii.

BL> Oil is designed to fucntion with this shit in it.

It is indeed, BUT eventually that capacity is consumed when
enough of the corrosive condensates have been neutralised.

BL> It only corrodes when the oil drains back into the sump.

Thats not even strictly true either, coz if it was you could
just have say a stainless steel sump and not give a damn.
@EOT:

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