In a message dated 3/13/2010 12:27:11 P.M. US Mountain Standard Time, jeandelucca at aol.com writes: i have some newly purchased castrol diesel motor oil. can it be used in the corvair engine and for that matter in the 283 v8 engine? thanks, jim YES, if it has the SM, SL, or previous rating in the donut. Regards, Bob Helt