[Locke]

Originally Posted by burn_this_city

If the car leaks oil avoid using synthetic. It penetrates the gaskets better than regular oil and will make the leak worse. I use it in my truck to extend the drain intervals. I typically get 15,000km between changes. Its better for vehicles using turbo chargers. When you shut down the motor while the exhaust is still hot, the oil in the turbo bearing will coke potentially causing premature turbo failure. Synthetic is resistant to burning up compared to conventional dino.

This is important.

If your car is older, then conventional oil and all of that 'nasty grit and gunk' is pretty important. Synthetic Oil will clear all that grit an gunk out of your car, but in many case that crap is plugging the holes that keep your engine from leaking Oil.