Alright...it's about time, and I have to decide. I gonna run a 15w-40 "diesel" oil in it, and I have to decide between the big three...rotella, delo, or delvac. I know I posted something like this before, but I thought I'd ask one more time. Is there any reason I should pick one over the other?? So far, it looks like my choice is between the Delo 400 and the Delvac 1300 Super...both have pour points that seem to meet 10w specs (and Mobil advertises this point). Rotella doesn't even seem to be close in this regard (although I could be wrong) Thanks for any suggestions. Justin.