Ok, I understand that gravity will cause it to have some pressure. That's pretty self-explanatory.
However, I don't understand how gravity would cause my friends nissan to come out in a nice stream and also cause the subaru to explosively evacuate? Is there something unique about the engine design that causes that much pressure to stay in the system?
I'm just trying to learn if this is something I just have to deal with or if there are ways to prevent it. I've watched lots of folks change their oil and I've never seen the amount of pressure that I saw yesterday. Ditto the two folks that were lending me a hand.