Contour Enthusiasts Group Archives Forums Modifications Duratec Maintenance How long does synthetic oil last?

I'm curious, for those who run extended drain intervals with any oil (say over 5k miles) - what does your new oil look like say 3 days or so after the oil change? Does it look exactly like it came out of the bottle or does it darken up immediately?

My main concern with extending drain intervals is that even if the lubricating properties of the oil are fine that it may saturate with "gunk" and start letting conaminants fall out of solution and form sludge deposits. Quick darkening of new oil is an indicator that the old oil could no longer hold all the crap in solution, leaving the new oil to pick it all up. I know that regular 3000 mile changes with run of the mill mobil leaves my oil looking brand new for weeks after the oil change.