interesting i have never thought of it this way, both sides of the argument has enabled me to look more into this. I remember, my friend was taking a shop class and asked me to come in one day. They were playing this video sponsored by valvoline. The video was saying things like "Its never too early to change your oil. The faster your change it the better it is for the engine, valvoline cares." I guess its all marketing.. no better to spread it with the use of our future mechanics.