I always flush with a cheap 10/40 'supermarket' oil. Run it for a few days in that, then use flushing additive. Never had a problem and the oil I drain out initially is very rarely black, usually deep golden.
I prefer to run it for up to a week before the flush oil (minimum a few days) so don't want to run it on the wrong type of oil really.
I always flush with a cheap 10/40 'supermarket' oil. Run it for a few days in that, then use flushing additive. Never had a problem and the oil I drain out initially is very rarely black, usually deep golden.
If you were going to do that, wouldn't you want to flush with a cheap supermarked thinner oil like a 5w30 or even a 0w20 so that the thinner oil brings out all the crud?