The trouble with making absolute claims beyond death and taxes is you’re typically setting yourself up to be proven wrong. I pay $0.20/gallon less than 87 for diesel and have done the math based on a direct comparison of my ‘18 3.6 and ‘20 3.0 driving the same roads in the same conditions...I start saving money around 60,000 miles taking into account oil costs, fuel additive costs, DEF etc. Oh and 9 quarts of MS-12991 Pennzoil Platinum 5w-40 go for $75 on amazon and walmart. I didn’t buy my 3.0 to save money, but that doesn’t change the fact that I will. I’m well aware that I’m the minority of folks who will, but that’s the rub with words like “never” isn’t it?Well, not exactly.
The Pentastar 3.6L spec reads exactly the same way the EcoDiesel 3.0L spec reads in the manual. "Under no circumstances should you ever exceed 10,000 miles" on an oil change cycle. If you go by the oil life monitor on the dash, both engines will typically get to 0-5% life remaining at 8,000 miles. So there is zero added oil life range with the diesel.
I just changed the oil in my EcoDiesel a couple days ago, at 4,228 miles. First one, so I did it early. The oil life monitor was already down to 46%.
Doing it myself at home for the absolute least cost possible, the Pentastar was $25 for synthetic oil that meets spec and a Mopar filter. The EcoDiesel is $100 for synthetic oil that meets spec and a Mopar filter. That's a 300% increase in basic maintenance cost for the diesel. Oh but wait...every second oil change with the diesel also requires a new fuel filter at a minimum cost of $40 so that pushes you to 460% more cost than the Pentastar.
It's true that we've hashed this to death. But a guy should NEVER buy a diesel to save money. You will spend more money, not save any.