It is always good to see the old Dino vs Synthetic Thread, 10, 298, 764, 101 edition of it of course.
When Dino oil did not have detergents in it some 30 or 40 years ago, there where many that changed to the New Mobil 1 oil and some how everyone mysteriously acquired oil leaks all over the engine.
This issue was related to the sludge that had built up in the motors and caked all over the edges of anything that was still in the engine. Places like the oil pan gasket, the valve cover gaskets, the rear seal. This sludge and crud was then dissolved from the newly develop very effective lubricant. Those seals and gaskets where now dry and cracked from not having been in contact with oil for 3 years.
Boom, the myth is born, Synthetic OIL cause leaks!!!
Dino Oil has for many years had detergents to solve this previous issue and most engines even with just Dino oil are fairly clean compared to a 1975 Chevy 350 inside.
The still exists today with Dino oil it is just not as bad. And the symptom of an oil leak after switching to Synthetic is that just a symptom of the problem of a failed gasket or seal.
The thing to know about Dino oil is that the very minute you point the oil in your vehicle and start it up the oil is starting to die, it is failing more and more with each and every heat cycle. And what I mean by dying it is chemically breaking down the molecules are being damaged and malformed and its ability to do its job is decreasing.
Synthetic on the other hand does not do this, it is not a wholly natural product. It is chemicals that form a fluid that is better at with standing both high and low temperature operation.
Synthetic oil fails after it is contaminated with gas, carbon, and NOx these form acids in the oil and are harmful to the engine. These elements are introduced into the oil over time and are pushed past the rings and valve guides in every single engine alive today new or old. It is just part of the process.
Switch to synthetic and resolve the failures in the gaskets and seals and enjoy your vehicle for much longer.