I haven’t wheeled my LR3 yet, just driven around on some dirt roads and a few mud puddles.
Well, go get stuck first on street tires and learn in that process that everything Blaise is saying is not only correct but well tested. You're falling into the rabbit hole of nonsensical imaginative scenarios that for the most part, don't exist or are at least superseded by the highly functional balance of keeping the struts in their neutral position as much as possible, i.e. 50/50-60/40. All this "extra" up travel you think you'll add and somehow benefit from at high speeds is basically little boy toy dreaming (we've all done it, but get past it before you screw stuff up).
While Blaise is fairly new to the lr3 specifically, he also dug in more than most people and really researched and tested some ideas. Hence his arrival at the tire size/ ride height.
I've been using mine right to and past it's limits since buying it in 2007 but also arrived at the sensible and highly capable non-rod lifted strut approach. You can use a 32" tire, the referenced 275/65-18 on factory lr3 wheels with no spacer or rods but you do have to complete the physical modifications such as moving the rear hvac lines, flattening both rear wheel well metal standing seams and associated plastic, as well as the wiring loom up front on driver side. Factory bumpers may also be a problem during full turns.
Rods: A. dumb B. more dumb C. only useful when combined, as necessary, with the strut top spacer (struts end up at factory 50/50 but vehicle sits 2" above the factory height. No loss in proper suspension travel, minor losses in ideal handling dynamics but any change of course reduces the factory engineered geometries.
Wheel spacers: A. looks cool, obviously. B. worsens problems inherent to this vehicle in terms of tire clearance while turning as well as fender flare contact at full articulation. People, in this thread, who claim it helps with vehicle track width first solved nothing by adding rods but then screwed it all up in the process.
Strut spacers: the only true "lift" that increases anything the vehicle cannot already do by itself (rods do nothing but just put the vehicle higher all the time, they do not in fact increase the maximum available height - they are a scam in claims of that purpose). LR3's simply set 2" higher handle like crap at speed, cornering, essentially making it more dangerous IN ADDITION TO making the compressor run more than it was intended LOL.
You know why ALL high performance air suspension vehicles allow higher speed LOWERING? It's because lower is better as highway speed, not 2" higher LOL
Now, you want to run gravel roads a little higher? Fine, it's mostly unnecessary, but just use the GAP or LLAms to add a bit during those times. 2" is more than needed though and actually seems to be less good in strut performance than standard height. 20-25mm seems just about right for the worse tracks.
To sum it up, stick with 265/65-18 unless you're willing to do the physical mods. With those mods, including mandatory tire relocation, you can then 100% run 32" 275/65-18 on an lr3 with no wheel spacers at all factory heights, no problem, slammed to extended.
I run that tire size year round for various trip types. This winter it was 8000 miles on michelin ltx winters. Standard summer tires vary but the strut spacer allows for up to 34" still with full lowering into a garage, etc.
One benefit of a 32" etc is that you can use lower psi while still retaining fairly decent ground clearance and not need to compensate by raising the suspension past it's ideal ranges. For example, on the 34's at 22-24 psi the ride over rougher terrain, even at a bit of speed, is still fantastic due to the psi but also the suspension is at it's normal zone seeing as the tire size itself is providing plenty of height for gravel double tracks and such. The most carpet-ride setting is +20mm on the 34's set to 22-24psi. Keep in mind the psi, for another thread, is entirely vehicle dependent because mine can weigh 7000-8500 lbs while a stock one will still feel like 24 psi isn't all that soft yet. You can see this in the sidewalls if out with someone else.
There are some slick equations for tire deflection per vehicle weight but I don't have my hands on one. You can understand though that a 6000 lb vehicle can use a lower psi to have same effect as an 8000 lb on same tire size, etc.
Hopefully this was useful as it is probably the 1000th thread on the topic LOL
But I'd put lots of stock into why those numbers were chosen. I also have a GAP tool and I do use it for exactly what you said, to add 1" and be able to go over 25mph, which is a huge benefit here on WA forest roads. +25mm gets you to a 60/40 split which is still acceptable, above that it gets into Johnson Rods territory. I'm not sure how much you've wheeled your LR3 vs your D1 (no experience in a D1), but I have an awfully hard time getting it to lift a wheel compared to my Xterra (with IFS) or older Jeep (solid on both sides). There's 10" of travel up front and 13" out back... I can't even use my jack without a spacer to get it off the ground!
