[4th Gen : 01-07]: A Word on Synthetic Oil, Leaking valve stem seals
Professional
Joined: Oct 2014
Posts: 116
Likes: 1
From: Summerfield, Florida
Everyone has their own opinion about engine oil. I buy the best fully synthetic (in my opinion) that I can get. About $8 a quart for 0W30. I have 3 high mileage vehicles. None use oil and none leak oil. I think I am getting what I am paying for.
Grand Champion
Joined: Feb 2015
Posts: 7,435
Likes: 578
Old thread resurrection! Synthetic oil has a smaller molecule to that of conventional oil so it can "find" a way out (leak).
http://www.cenex.com/about/cenex-inf...gine-oil-myths
http://www.cenex.com/about/cenex-inf...gine-oil-myths
Myth #3: Synthetic engine oils can wear down seals in an engine and cause leaks.
This is an often-cited myth. In fact, if your seals and gaskets are in good condition, synthetic oil will not leak in your engine. Synthetic oil has not been shown to deteriorate engine seals or gaskets. But it might find an existing leak. The smaller molecules of synthetic oil are able to pass through very small cracks and crevices that the larger molecules of petroleum-based oil cannot. Eventually, those small cracks and crevices can lead to bigger problems — with or without synthetic oil.
This is an often-cited myth. In fact, if your seals and gaskets are in good condition, synthetic oil will not leak in your engine. Synthetic oil has not been shown to deteriorate engine seals or gaskets. But it might find an existing leak. The smaller molecules of synthetic oil are able to pass through very small cracks and crevices that the larger molecules of petroleum-based oil cannot. Eventually, those small cracks and crevices can lead to bigger problems — with or without synthetic oil.