If VR1 is priced right, use it. Its not priced fair up here in PA. 15w40 diesel oil has a good amout of zinc and is available almost anywhere up here for $12-14 gallon. Thats what i use in my tow truck, etc. So it only makes sense to me. Not to mention, ive asked about oil previously on here and 15w40 was highly recommended by many, to put in about anything.
