I can't speak to the recycled part, but for years, 15w40 Delvac 1300, and now in my fleet's case, 5w40 Delvac1 has worked well in our mixed use fleet for years. Our school buses are Cat and now Navistar, our 60 A buses are 5.7 and 6L gas, and we run a bunch of... Login to read more.