I have been using 5w30 in my 2007 F150 Harley Davidson 5.4 3v V8 for the past year or more with great success. I prefer it over 5w-20 for noise and feel of the engine. I have gotten my best fuel economy using the slightly thicker oil and sleep well at night using it. Not trying to start a thick vs thin debate as I'm sure that horse is pretty beat at this point. But I have access to this Delo 400 LE 5w30 api-sn/cj-4 oil for pretty cheap through my wife's work. They use it in big rig trucks and buy it bulk and are willing to sell for cost to employees. Anyone use this oil in a gasser? What do you think of me using it for my main application? I haven't found much info on this oil yet. Just a pds from their website. For the cost for full synthetic I'm thinking of using it in as many things I can as it is cheaper then most Dino oils that I have access to. Any input is much appreciated!