Since the pickup engines have become electronic, if everything is ok, they will start down to 0 without being plugged in. As much as these engines cost to repair, I would use a synthetic oil or a quality dino oil such as Shell rotella, Chevron Delo, or Kendall Super D and not go for an extended drain period. The Cummins is by far the most trouble free and built like a Class 8 diesel (you should see the crank, block, and rods). The Isuzu should be ok if Isuzu did more engineering on the engine than GM did. The Powerstoke does a good job but I don't know how people afford to fix them. Water pump $240, injector driver control module $600, high pressure injector oil pump $450, injectors $300x8, glow plugs $13x8, injector control pressure switch $200, camshaft sensor $90, rebuilt turbo w/pedestal $800, fuel supply pump $100. These items start to fail after 125,000 miles. These prices are plus labor. If you get diesel fuel in the cooling system-you have to pull the heads to have the injector coppers replaced. Diesels are great for certain people, just know the associated costs of repairing one if you keep it long enough or buy a used one with over 125,000 miles. We have never replaced a powerstroke or T444E in an Navistar. We have done all of the repairs noted in this post. You shouldn't have to justify the purchase to get a diesel. You only live once, if you want one get one.