If you start your truck in very cold weather synthetic is the way to go! many run synthetic in winter/dino in the summer.
i'm in a warm climate for now, so i'm happy with dino! i like delo 15/40, next mobile delvac 15/40, and rotella 15/40 like you are using. for synthetics i like mobil, and rotella 5-40. IH suggests delo 15/40
A forum community dedicated to Ford F-series owners and enthusiasts with a Power Stroke diesel engine. Come join the discussion about performance, bulletproofing, modifications, classifieds, troubleshooting, maintenance, and more!