That is an interesting thought. I am unsure how much extra fuel I will lose from the larger tyres (I am moving from a 30" to a 32"). I didn't think 20mm would make such a difference in the alignment -- some LR3s drop that when over 80mph as a factory setting!
Just to review, I went with the KO2s (a decision led largely by their 31.8" diameter). I ride at the stock height, though the driver’s front tyre brushes occasionally on the front bumper to wheel arch liner mounting screw. I have on the RRS rims which provide the same track as the original rims (though the 1/2" width increase is distributed by a 1/4" offset decrease). In my opinion, a further decrease of 1/2"-1" would remove the rubbing on that screw altogether. Of interest is the fact that there is no rubbing on the frame horn or UCA. I did move the bumper on the adjustment screws by 3/4" forwards and cut 1 1/2" off the lip at the bottom of the bumper where the wheel arch liner meets it. I pushed the wheel arch forward by about 2" below the headlamp assembly -- which was made difficult by the washer fluid bottle. Now this mod has been made, no fouling of the wheelarch liner occurs save the screw that sits proud of the wheelarch liner at about 12 minutes to the hour. On the trail, there is some slight rubbing at stock height from the front due to articulation. The rubbing is so slight that I cannot see indications of the rubbing when back on firm ground. The rubbing is not present at off-road height.
I had the alignment done at stock height (prior to that, there was no rubbing at all!); raising the vehicle to plus 1" shifted the readings to a position still within tolerance. Furthermore (though I probably won't use it) a 1/2" lower from stock height to 'highway' position also forces the alignment to alter -- though the deviation remains within tolerance. In other words, if you align the vehicle in the centre of tolerances at stock height, the vehicle is still within tolerance with both a 1" lift and a 1/2" lower. However, these are the extremes of tolerance.
I should also report a 1mpg decrease in fuel consumption on highway use; in the city, consumption is roughly the same but bordering on a slight increase. I have no idea how the KO2s work off-road or in snow yet, but they are quieter on road. Indeed, the steering is much lighter than with the Duratracs. However, despite having 33psi front and 41 rear, the vehicle is like riding on rails and is very jarring in a way that the Duratracs weren't. I am not certain if I will not take them back after my 30 day trial and exchange them for Duratracs.
Here are a few photos for the madding crowd -- the thumbnail shows vehicle at an un-settled access height.
or going 275/55 Toyo MT(32.1”
