Ha, well, had you not said something, I may have found out about it too late. So, "feedback is a gift" my boss always says. I'm happy with the Tundra, it may take another week or so for my wallet to stop paining me in the @$$.
The conversation with the Tundra salesman, and my insurance lady were humbling to say the least LOL.
Frankly, the 5.0L Cummins was never very good. RAM was wanting a smaller diesel to offer in their 1500 series trucks, and because of the long standing relationship in the HD trucks, Cummins offered them the 5.0L V8 diesel. RAM tested the engine and ultimately turned it down. Their analysis is ultimately correct, completely not regarding any reliability problems the engine has: for the size and weight and number of cylinders, the 5.0L Cummins doesn't make very much horsepower and torque...but also doesn't get very good fuel economy either. RAM ultimately went with the smaller, cheaper - and possibly equally unrealiable - VM Motori Italian-made 3.0L V6 EcoDiesel, which was even less powerful but did achieve very good mpg. (As a side note - the 3rd generation of this engine seems to be reasonably reliable, but RAM is discontinuing it).
One of the issues in the 5.0L Cummins is the Bosch CP4 high pressure fuel pump. Ford and GM used it from 2011-2016 and had numerous fuel system failures with it due to "diesel contamination" causing inadequate pump lubrication. Once the pump began to fail, it would send metal shrapnel throughout the entire fuel system, including the injectors, lines, fuel heater / cooler, water separator, lift pump, and filters. Typically on a Ford 6.7L or GM 6.6L diesel, the dealer replacement cost of the fuel system could be $10k or more. And since the failures always seemed to be caused by "fuel contamination," most of the time warranty wouldn't pay. Starting in 2017, GM ceased using the CP4 and began using a Japanese Denso fuel system, which seems to have a reasonably good track record (however, high pressure pump failures have occurred in these as well, just seemingly much less frequently). Ford made some modifications to the pump, including a hard slippery coating on pump pistons to help provide lube in the event of diesel contamination. Since 2017, Ford 6.7L engines with the CP4 pump have continued to fail, but seemingly at a far lesser rate than previously.
Up until 2019, the RAM HD trucks with the 6.7L Cummins engine continued to use the very well proven and reliable Bosch CP3 high pressure pump. However, for the 2019 models the engine was updated and began inexplicably using the problematic CP4 pump. The problems were so numerous that RAM/ Cummins modified the pump after just one year, and completely discontinued using it after the 2020 model year; reverting back to a modified version of the CP3 pump. There is a major recall on CP4 pumps on RAM vehicles, and this includes the EcoDiesel which also uses this pump (However, with less fuel volume demand the CP4 failures in the EcoDiesel seem much less).
Of course Cummins used this pump on the 5.0L engine as well, and suffered all the same problems as everyone else. Unfortunately the 5.0L engine is also not super easy to work on, and to compound the problem - Nissan mechanics are not diesel mechanics in this country and really had no experience. Some very frustrated owners had their broken down Titan Cummins trucks towed to heavy truck repair facilities which have tons of experience working on Cummins engines. However, very few were willing to work on this 5.0L engine. The 6.7L in the RAM HD trucks was familiar territory, having been used in school buses, large straight trucks, delivery vehicles, etc...but not the 5.0L.
Anyway, long post, but ultimately I think you made the right decision. I prefer domestic pickups, because I don't buy into the "Japanese magical reliability" mantra one bit, but I think your new Tundra will serve you very well. The Tundra is powerful and has an exceptionally large rear axle for being a half ton. Likely larger than what was in the Titan XD. And even though Nissan marketed the XD as being a "heavy duty half ton," even when they introduced it there were already Ford F-150's that could tow over 13,000lbs which is more than the diesel Titan was rated for.
