good info. i am not to fond of royal purple. certain motors just do not like it. a friend whom races a vette in scca has went through 2 engines and the only hing in common with both of them were that he ran RP. since then he changed to mobil1 and its all good. it could have been a coincidence but i have heard this from a few other drivers at the last enduro i worked, most seem to prefer castrol or mobil