Most folks who install 18" wheels on the LR4 (Compomotive PD1880/81 with ET44 or even LR3 or RRS OEM 18s - but the latter ones only fit with spacers) run either 285/60R18 or 265/65R18, very similar in overall dimensions, as there are many good choices in those sizes- including E rated - and 31.5" is pretty much the largest diameter tire you can run without some sort of lift on the LR4. Especially when new, the front tires will rub slightly on the frame horns at full lock (my horns kind of "wore out" over time due to such rubbing), but will still allow you to drive away should disaster strike one day, the air suspensions crap out and you find yourself on the bump stops. The spare will need to be deflated and I also had to remove the heat shield separating spare wheel well and exhaust to winch it up, but it fits.
Lift rods trick the EAS to "artificially" raise your car 1.5 to 2" all the time, that's about it. Lots of cons about driving around lifted like that 24/7. There are electronic modules that can do the same more elegantly - at the touch of a button (LLAMS and MudTech, there may be others) - so you only lift when you really need to. Or get an IIDTool from GAP, it costs a bit more but can do that and a whole lot more.
