Originally Posted by stoffius
is it okay to switch from regular to synthetic oil when the car has over 100k miles on it? what if the head was rebuilt? a couple people i asked said no because the thicker oil will have sealed any potential leaks and the synthetic would just wash it away. on the other hand, a few people have said no problem, it's a much better oil and won't do any damage. btw, no repost police please, i already searched.
I switched to synthetic at 140k. 50k miles later my engine has consumed far less oil than it did with regular mineral oil and I have developed no problems whatsoever. I don't really buy the stigma that people have against switching to synthetic...if your car is fucked up to begin with, synthetic oil will make it more readily apparent because of the smaller molecular size. However, if everything is in good shape, it should help longevity.