oil turn to black due to heat ALONE? i doubt it a bit..
surely most of the black thing is due to carbon built up right?
carbon built up due to many thing.. even when combustion, some
of the carbon (like tiny2 amount) will drop to ur oil..
ur engine oil MUST be kept in good condition (less carbon as possible)..
so that less friction to the piston and wall. thats y we chg oil every 5k km.
IMO, if engine oil is still maintain yellowish or brownish after 1 week..
and at same time ur exhaust smoke is clear.. talking generally i think it is a sign of
healthy engine.. correct me if im wrong..
u can see for ur self the oil after 1 wk at photo on page 1. it is not crystal clear.. surely.. but it is still yellowish. unlike before i flush, the oil turn BLACK only after 2-3 days..