Helihead

i use the rotella t 5-40 and change every two thousand miles. i know its alot but oil is cheeper than a motor. there is a artical called the oil guy i think and he says regular oil breaks down from clutch and gear sheer in about one thousand miles so you should never use it. use only syn and do not mix because you are adding the oil that breaks down eaisily. i will try to find the link and add later.