After long pondering I purchased Penz. long life 15w-40 for year round use in my 5.7 liter v-8. I feel the advantages are the strong additive package, 12 tbn, the ability to hold formation of acids in the winter to a minimumavalibility at Wallyworld, and the low pour point. -33 approx. pour point. I think the oil will flow well in the winter. This oil seems to flow better than other diesel oils I have researced. And yes the price 1.50 per quart or less compared to 3.00 plus for shell rotella synthetic. For my short trips and relative low miles between changes I could see no benefit to me using a synthetic oil now. What do you think? Good decision or a bad one? This oil seems like a good choice.