well.... im gonna try and sound like an expert cause i was told this by a mechanic when my dad would coast his 78 toyota truck down our hill to work everyday, sometimes he didnt even turn the car on and eventauly it caused a problem ...... but i realy dont remember what he said..... something to the extent of theres not the equal pressure of oil required to lubricate or something..... i dunno.. you guys try work off of that