JW51 GM tells you to use 5w30 in their light duty trucks,it's on the fill cap. Using 30w cut with a quart of kerosene in the cold seems like asking for it. (that is in the big service manuel) Now I don't suffer with sludge in my straight propane burners ,5 of those, 216,48-235,3-late 235's so to answer your question yes getting along fine since oh 82. If 5w30 was even available then.
