I just purchased three 2 gallon jugs of Mystik JT8 15w40 for $43 shipped. Going to use it in my 2015 Ram EcoDiesel next oil changed after our 4th of July camping trip. I'll run it my usual 5k interval (manual says 10k) and get a UOA done. Capacity os 10.5wts so this will get me two OC with a lottle extra for topping off. It'll have a few trips towing our Jay Flight Baja on it too. So far I've ran 5w30, 0w40, and 5w40. I'm wondering if the HTHS 4.3 will show any better wear but my main intent was a low cost oil change that should give the same results as a 5w40 synthetic.