Will synthetic motor oils cause engines to leak oil ?

No. Synthetic oils do not cause engines to leak oil. In fact, the products we carry are fully compatible with modern seal materials and is properly formulated to condition seals, keeping them pliable to prevent leakage. We have heard cases where switching from petroleum based oil to synthetic resulted in some leakage, however, this condition usually exists in older vehicles or vehicles with high mileage that have always used petroleum based oils.

Over time petroleum based oils will cause gaskets and seals to crack and become faulty, however, the sludge build up from petroleum oil plugs up the areas where the gaskets and seals became faulty. When a switch to synthetic oil is made, the cleansing chemicals in synthetic oils can sometimes unplug the sludge plugged areas which could allow a leakage could occur.