....like a few-year-old Range Rover or Range Rover Sport. I am, however, afraid to change totally problem free ownership ....
Facts: I've owned my 2007 lr3 since new. I am the "type" to have the best tech work on it or pay a little extra to know things get done properly. So, it's only been touched by trained rover techs. I have a warranty up to 100,000 miles (it's at 99,850 this week!) so there has been no reason anyway to try "saving" a few $ by going to anyone other than a dealer I find to be better than another dealer or an indy shop such as Flying Circus in Durham NC or Columbia in Portland.
Oh, Mike, I forgot, chat with them about rovers.
Ok, I was about to go off on an "opinion" tangent
More facts:
You like going places where tire choice and sidewall profile comes into question....there are tire and wheel size limitations on any vehicle in the world, but some are found quicker
LR3: factory stock vehicles came with 18" and 19". Minimum rim size for stock vehicle, using factory wheels: 18". Lucky8 is trying to develop a 17" steel with offset similar to adding a spacer on an 18" alloy. This 17" is still not readily available. Offset on lr3/4 actually can introduce other problems so just pushing the wheel out is not an entire solution. (when wheel is turned, the added offset actually brings a wider tire into certain contact points sooner...)
LR4 comes factory with 19" or 20". Stock vehicle can only fit factory 18". OR, "Compmotive" 18" aftermarket wheels can be bolted on directly. They are apparently forged so in some ways, an "upgrade" from factory alloys. Keep in mind, with heavy vehicles (my lr3 is 7000-8000 lbs when fitted for trips) wheel load rating is something to remember. The factory alloys are all suitable and so is the compmotive, but nobody has found a suitable alternative for the lr4 yet that I've read.
Why the size restrictions? Front brakes. Rotors and calipers. Some people have fitted v6 model sourced brake parts onto lr3 to allow fitting the v6 spec 17" wheel that other parts of the world have available. North America basically only ever had v8 ordered with a very few v6 floating around. Similarly, I thought Scott Brady looked into fitting lr3 spec brakes onto the lr4 build to allow simplest use of factory 18" wheels.
The compmotive 18" may be "better" because they're forged, but they do not look at all like they match the Land Rover. They're not terrible like the rockstar wheels on toyotas

but they aren't rover-like. Also, as I mentioned, the offset can become it's own problem creator if trying to use wider tires.
The upper control arms, and some weird frame steel "horns" behind front wheels, cause contact points on wider tires. For example, a 285/65x18 will rub UCA flange metal whereas 285/60x18 will just barely work without touching. The front independent suspension is an interesting thing I've seen when on a lift with tires drooping fully. It's at full extension that the UCA becomes the tightest. Makes sense when you think of basic geometry. I have 275/65x18 and they just barely work without rubbing the UCA. I suspect that a 265/70x18 MIGHT work but then it's tall enough that it could also slide into the danger zone. You think "add a spacer", well, maybe for that aspect but then the width of the tire will now rub at approximately 70% turn onto the frame "horns" or front fender lining or ARB bumper trim metal (which can all be cut away). I think my 275/65x18 would rub the frame horn for sure if using a 25-30mm spacer. I may test this soon. I have the spacers but my frame horns are removed.
Maximum tire size on lr3 or 4, stock vehicle 31.5", period. Modified 32", getting goofy and riding too high all the time, I suppose 33" could work, but you'll actually be stuck on yourself if the computer system ever decides to drop to the bump stops. 33" tires will actually make so much contact inside fender liners the vehicle would rip itself apart trying to move. So, annoying mods allow 32" tire.... but, the way the air suspension works, you can get quite the ground clearance even under center, all the way through, with just the 31.5" tire and no mods at all.
In the Land Cruiser, a stock lc200 or lx570 can fit a 33" tire no problem. That's a 275/70x18 (too wide would also cause similar troubles with UCA but that's about the only
really tight spot in the fenders. Also, 17" TRD wheels can bolt right on over the brakes. Sweet right?!
That's before the straight forward OME 2" lift.
ARB has lockers for lr3 or lc so that aspect is basically the same.