With light duty diesel motors, and light duty diesel motors shared with lighter medium duty trucks, it is not a matter of *if* you will have to do a major engine overhaul. It is a matter of, 'when.' Unless you are looking for power and fun, ignore what you hear from the Cummins, Powerstroke, and Duramax enthusiests and recreational drivers. The Big Three are all struggling with potentially devastating failures. Chevy was smart to temporarily bow out of the medium duty truck market (they re-badged Isuzus). Ford, which struggled more than the others from 2003 through about 2013 has now managed to produce a medium duty diesel that *should* last much longer than the others by offering a de-tuned version of it's 6.7 in the F450 and F550. It should also compete with the heat/EGR troubled Cummins and Duramax in the up-powered lighter trucks just fine. However, the Ford's are still plagued by hard-to-pinpoint intermittent and consistent sensor failures, some of which can lead to catastrophic motor problems. (Just as the Duramax and Cummins also have serious cost vs engineering challenges). Frankly, the only way to get your money out of a diesel truck is if you are towing well over CDL mass (more than 10,000lbs) and burning at least 50,000 miles a year, and/or you plan to dump the truck on the used market before the odometer/hours cross a threshold set by your savvy fleet manager.

Current diesel motors are a big money pit once you get over about 175,000 to 220,000 miles of private use, or the equivalent hours of pro use. After only 200,000 miles, or the hours equivalent, modern Super Duty/Ram/Chevy chassis and cabs still have a lot of life left in them. As a little guy, I need that life. Truck down time can break me. Once I realized I could source a fresh Triton V10 for the cost of tearing down a fouled EGR system, or replacing trouble prone diesel injectors there was no turning back. When it comes time to do an engine swap on that grenade-d diesel, you are looking at $9,000.00 if you are connected, and $15,000.00 or $16,000.00 at the dealership. And you _will_ have to replace that motor. Especially if you run a tune to dodge the EPA regs.

If you like that power as much as I do, and can afford it or trade it in every couple if years, have fun!! Or, if your business makes diesel the right choice (hot shot, expeditor, big fleet, etc), I get it (and I'm jealous a little. But if you need to wring every mile and operational hour out of that truck, you will love that big gas lump under the hood, even as you pull to the right lane going up the mountain. Smile when that kid shoots you the middle finger passing you on the hill. Lol.

I hope this helps some one avoid the traps I fell into. If any fleet managers want to correct or modify any of my points, I understand. Thanks in advance for any up-to-date input/advice on the reliability of the latest gas motors in the Ram and Ford medium duty trucks.