Sorry I'm late on replying,, but somehow missed your posting.
I alway's like to see post's like this showing High Mileage Nissan Truck's,, especially Hardbody's and Frontier's.
I had my 1st Nissan Truck '93 4cyl KC AT that I drove for 20 year's/174K mile's. I tried to keep up with the preventative maintenance and the Motor was still running smooth and quiet when I sold it. It's the primary reason that I wanted another Nissan Truck,, but with a bigger engine so that I could pull a heavier Utility Trailer.
I discovered and learned quiet a few thing's doing the preventative maintenance on the '93. 4 thing's that pay for themselve's many time's over is Cheap Neoprene Seat Cover's, Floor Mat's, a Steering Wheel cover, and a console cover.
Driven with care and doing the preventative maintenance make's a Big difference in how long these truck's will last. I just read on another Site about a fellow that has a '15 Frontier with 50K mile's. He said he's only changed the Oil 2 time's and is alarmed that his engine is makeing noise. I can't believe these guy's that fall prey for the extended oil and filter changes. No matter whether it's Synthetic or Not,, The Oil still get's dirty and needs to be changed out on a regulars basis like the Owner's Manual/Maintenance schedule say's to do. I have done Oil and Filter changes every 6 month's or 5K mile's and my engine 4L V6 is nice and quiet on Startup as well as under driveing condition's. I recently switched to Castrol Full Synthetic Magnatec but haven't really noticed much of a change; Maybe just a tad smoother/quieter on Cold Startup. I switched because this is the 1st Synthetic Engine Oil that say's it leave's an oil film on the Oiled part's even after the engine is shut down for an extended period, and because I'm thinking that the Full Synthetic will hopefully make my engine last longer.
When I took off the 3rd set of seat cover's on the '93, the Seat's still looked just like Brand New,, Not even faded. 1st person that looked at it,, gave me 4K $'s. I don't think that's too bad since I paid 10K brand new.
I remember many years ago a guy was driving a couple hundred miles each way to work in an old Datsun pickup. It had like over 500K miles on the original motor and Nissan actually presented him with a new truck. All highway miles and proper maintenance and I can see more moden cars lasting that long but this was a Datsun. How long was that? '70's? Back when 100K was a lot of miles on a vehicle.