Quote:
Originally Posted by Meat Head
If you read the entire thread you will see that I'm not saying drain for hours  . I'm saying if you let the car sit overnight (do not start before draining), it is equivalent to draining for hours because the oil has gathered at the sump. At this point 30min should drain every possible bit of oil out of the engine. If sludge is your concern, because the car was parked at operating temps, I would assume the sludge would also gather at the sump at this point. |
As you say, what you are doing is equivalent to leaving it to drain for hours. And as I've said, not convinced of the benefit of that.
Mr Knowles has made the clinching argument, I feel. That sludge that has collected over night may not be terribly mobile when you attempt to drain cold the next day.
Drain it hot and nicely mixed up and you can be confident you'll be getting the vast majority of the unwanted gunk out.