Last week I sought input from BITOG as to why Castrol "warned" about using 5W20 in engines for which the manufacturer did not make a 5W20 recomendation. By the way, as far as I could tell, only Castrol used the word "only" in their recomendations. Last night I noticed that the back of Redline's 5W30 that they warn against using their product in the first 3000 miles. "not for break-in". So, does the group think that Redline is using marketing double speak to make us think that this stuff is so "slick" that your rings won't wear? Or, do you guys think that Redline has experience and data that forces them to try to restrick their product from use in new engines? Are they just being responsible or being salesmen?