What's the word on the Castrol Start Up? I have a '00 Silverado 5.3 with only 19k miles. Its started every day, but usually only to back it up out of the back yard and put on the street during the day so the garaged car (daily driver) can back up and used. 427Z06 said the frequent cold start up will put more wear on the motor because its not driven much. Will Castrol Start Up help out. Is it snake oil? How does the oil "cling" to the metal and provide lubrication at startup? If the stuff works, why haven't everyone else offer it too? Will M1 work better? Is Castrol Start Up Dino, SynBlend, or GRP III Syn? Thanks for your experiences/advice/opinions/comments.