Good oil

[PKRWUD]

Originally posted by Dark_5.0
Synthetic oil cleans the hell out of the inside of engine which is great. But with an old high mileage engine the seals and gaskets are not what they used to be and the engine will leak oil if you use synthetic.

If you start out using synthetic when an engine is new then its ok to use it forever cause the engine is used to it.

But your not supposed to start using synthetic oil on a high mileage engine that is used to conventional oil.

Some people use synthetic oil on high mileage engines with no problems and some people develope oil leaks right away.

It all depends on the condition of your motor,

This is absolutely correct. It is generally considered safe to switch if the engine has 60k miles or less. There are many people that have successfully switched at much higher mileage, but I won't ever recommend it.

I personally use Mobil 1 in my truck, and Red Line in the Sprint car.