12-21-2015, 03:44 PM
I usually drain it when hot. I follow the theory that the dispersant additives in the oil (used to suspend tiny impurities in the oil and prevent sludge buildup) are doing their job when the oil is near operating temperature. The oil is also noticeably thinner when hot and definitely drains faster, and it may be my imagination, but I feel that the thinner oil drains more completely.
When it comes down to it, I'm not fanatical about doing it one way or another, but when it's convenient I do it hot.
Hot or cold, I usually let it drain for a half hour or more.
As an aside, my air-cooled airplane engine is supposed to be run to operating temp before an oil change to allow the dispersants to do their thing.
When it comes down to it, I'm not fanatical about doing it one way or another, but when it's convenient I do it hot.
Hot or cold, I usually let it drain for a half hour or more.
As an aside, my air-cooled airplane engine is supposed to be run to operating temp before an oil change to allow the dispersants to do their thing.