So I read the big post with the mechanical engineer and soaring.... and got pretty much that you should use synthetic if your running your car more than a few thousand miles a year.


Sooooo... if a car has been sitting for awhile... and just recently got a overhaul with less than 1000 miles on the engine again... then sat for a year.... how long do you run dino oil before switching to synth if at all?

 

I have always heard wait till you hit the 3-5000 mile mark on a new engine before switching to the synth stuff

 

seeing as how its a fairly fresh rebuild, if you switch to synth. u shouldnt have any problems with oil leaks on the seals.
alot of times motors get used to runnin dyno and the impurities in it form extra barriers, but when synthetic is used on a high mileage motor leaks often do occur.

 

What many do not know is, the leaks are caused by bad or cracked gaskets. The dyno oil tends to keep these little cracks sealed due to its nature. The Syn oil cleans that away and BANG, you have an oil leak. Much of the gaskets many years ago were made of cork and they dry out and cause the cracks. The gaskets today have compounds in the cork that prevent much of that problem.