What are your thoughts about using 0w-40 in a 2012 RRS with the 5.0L SC engine? The vehicle has 202k miles and we just had a ton of work done to it. Replaced the timing chains and guides, new fuel injectors, all new tappets, water pump, F & R cross over pipes and replaced the SC snout. It was mentioned that with that many miles a 0w-40 or 5w-40 oil could be used. Is this recommended or should I stick with the 5w-20 the owners manual recommends?