Bought some cheap engine oil from my local garage a couple of weeks ago because I had the low oil warning light on. Usually inuse mobil 1 5w 30 but I bought some autocare 5w 30 for 4.99. After putting some in, the engine idles smoother and accelerates just as smooth as the mobil 1. Maybe even smoother. The autocare oil stated that it was specifically designed for ford durotorq engines. So would using it long term harm my engine?