Quick question, i know the suggested oil to use for the 10, is mobile 1 ( in manuel) ...but im thinking of putting royal purple ? ...would it be that much more benifical? and how long do you guys wait to change your oil mileage wise? i usally do about 4 thousand...but people argue with me and say it can go longer...but they dont drive a 10:rock: ...(they drive a lexis ...mercedes) thanks Nick