There is a little leakage as the fluid vapors get released into the atmosphere from the faces of the seal, though. Since the quantity is hardly quantifiable, the seals are considered leak proof.
made of a yieldable resilient material having flat sealing faces and comprising two ring portions connected together by an annular portion substantially v-shaped in cross-section which may yield or expand as the mounting requires.
Motor oils typically include a few additives which can make up between 5% and 30% of the oil. These additives help enhance the performance of the oil. Motor oils can include the following additives:

MVQ

