On vehicles I plan on keeping around for any length of time, I just keep the fluids where they're supposed to be, in the amounts they're supposed to be, and pay attention to parts that are supposed to wear out. I mean, I have a big ol shop with a lift and all of the tools.. and I like to use them.
When I think about mileage, ill give a for instance.. about a year ago I sold my 97 Mustang GT convertible that I had bought brand new, back in my youth. Sold it with over 350,000 miles on the clock. Only "hard" part I ever had to replace was the fuel pump in 2015 (in the parking lot of an Autozone outside of Charlotte, NC.) Tires, plugs, fluids, exhaust, alternator.. those were all replaced over the years. But the thing never dripped or burned a drop of fluid. I wouldn't hesitate to drive it across the country in an instant... and I wish I hadn't sold it. Thought it was time to grow up a little more.. so I did. A month later went out and bought a '12 GT with 10k miles and a 6 speed. Immediately gave it headers, Boss intake, exhaust, a tune, few other little things
Last October we sold off the wife's Jaguar XK8 with 250k+ miles, it ate an alternator once.. other than that, not a single problem. Car before that was a Mercury Mariner we'd put 200k+ on. That one did eat a 2-4 band in the transmission, but that was a common problem.
So to think of 210,000 as a lot, just doesn't jive well with me.. not saying you're incorrect, because, you probably are not.. that just stinks. And I'm too busy to be slinging new engines in Jeeps, those days are over for me.
Anyways, I like the Jeep, it's paid for and does what I need it to. Not as much fun as an old 77 Levi edition I had, but it's got AC and cruise LOL
That's funny, I had 2 mustangs in my youth; a 91 Fox-Body LX with a 5.0L and then I traded that one in and got a 93 LX with a 5.0L (Both were 5 speeds) which I tricked out, Cobra upper & lower intake, 1.7 Roller Rockers, 65 MM Throttle body, 70 MM Mass Air Sensor, High Performance "X"-ECU, Superchips ADS performance chip, 3.55 gears in the rear, TREMEC 5 speed transmission, K&N RAM AIR kit, High Performance pulley kit, Electric Fan, 190 Liter per hour fuel pump, 3 Chamber Flowmaster Exhaust with a 3 inch stainless steel Basani X-Pipe with Hi-Flow Cats & BBK 1" 5/8 inch shorty headers, I also had a brand new B303 cam, E303 cam and GT40X Aluminum cylinder heads still in the box that I sold with it when I got rid of it in 2005. I lost my tail when I sold that car and didn't come anywhere close to getting my money back, as you can imagine.
I LOVED those 2 cars, but I had to grow up - and those 2 Mustangs caused me way too many run-ins with the law.
But, like I was saying - if you have those kind of resources and you are keeping on top of it the way you say you are, you might get another 150,000 miles out of it, who knows.
The only thing I can tell you from my time on this forum is, I don't recall seeing or hearing of anybody with a Commander, that has a Hemi with over 250,000 original miles on it.
Maybe they exist - and those owners just don't post here, but as I said, Hemi's are notoriously hot-running engines & that seems to be about the amount of mileage (250,000) where they start having major problems like dropping valve seats - which the Hemi's are quite infamous for and when that happens with the mileage that high - most guys will either opt for a rebuild, or, just replace the block altogether.
Maybe you will wind up being the exception - who knows.
Best of luck with her and your upgrades project .