Changing to synthetic oil in a high mileage engine

Is It Safe To Put Synthetic Oil In A High Mileage Engine? - YouTube
Is syntheticoil bad for old engines? Maintenance repairs car can be used in older vehicles? Syntheticoil appeals to me because the winters here can get pretty cold risky switch from conventional enginesyntheticinahighmileage car? I changed back regular castrol and put new set of plugs it.

What is your opinion on changing from conventional motor oil... - Quora
If the engine is running fine changing over tosyntheticoil can only make things better, but could reveal leaks that are currently being blocked by engine

What Are the Risks of Switching to Synthetic Oil in Older Cars?
Syntheticoil offers several advantages of conventional oil. It copes better with temperature changes and does a better job of effectively lubricating various components in the engine.

Switching from Synthetic Oil to High Mileage Engine Oil - Forum
On highmileageengines do not change the type of oil. In fact I will not change brand. On a previous highmileage vehicle (diesel powered pickup) I changed from regular oiltosynthetic. I had engine failure about 2,000 miles later.

Change from regular to full synthetic oil with high mileage - Forum
When synthetic first came out oil leaks were a problem when you changed from regular oil. This problem was eliminated many years ago by the oil

Q&A: Should I switch to high-mileage engine oil?
What makes high-mileageengineoils different? High-mileageoils have ingredients to take care of older engines, like conditioners, seal swells, antioxidants, detergents and wear or friction additives. Typically they use a viscosity modifier that is durable and won’t lose viscosity very easily.