Hmmm....Id love to get these tyres next time round. I've found with the KM2's, their tyres are .2 of an inch smaller than KM1's....dont know if that makes a difference for anybody.
The benefit of the tall and narrow tyre is that you get more pressure and a longer sirface contact patch than the equivalent wider tyre at the same pressure....You can also run a lower pressure easier off road and thus the tyre will mould itself around obstacles better thus giving you more grip.
Wide tyres are for floatation and are better on rocky terrain, narrower tyres are better load carriers and work better in muddy terrain as they cut into the mud easier searching for the hard ground below.
Theres an awesome writeup off the Expedition Portal website in the US comparing 255's to 285's.
Here it is, I found it...the well documented case for a narrow tyre over a wide one, this should be read by almost everyone as it is an awesome technical document.
http://www.expeditionswest.com/research/white_papers/tire_selection_rev1.htmlHeres what I was trying to explain above -
Now in regards to lift required....yeah just fishin has a 2" lift but I would recommend a tad bit more than that, and if you going to be using the full suspension travel you may find that you need to trim a little.
The 255 also fits better on a 7" wide rim than an 8" wide rim, the bead holds tighter, but I have seen many running them on an 8inch rim on Yank forums without problems. You will need if a 7inch rim atleast a +20 offset to move the tyre away from the Upper Control Arm, as most tyres below this diamter are able to tuck in just under the outer edge of the UCA where a tyre of a true 33" diamter or more sits beside the outer edge of the UCA. +20 to +10 would be ideal.
I have been considering this tyre for a while, and even thou they are not that popular from many brands they are an effective offroad tyre non the less. I have heard they weigh the same as a 265/75x16 (31.8") tyre and have also heard of fuel economy improvements from running them....but dont forget, the increase diamter will put your diff gearing out.
Other bands that make them are Maxxis Bighorn (33.3/10.1x16), Toyo Open Country Mud Terrian (33.5x10.3x16) even thou the toyo's arent sold in australia, I have looked into it and they dont even plan on bringing them in.
Heres a pic below comparing the Toyo's and Bighorn's side by side-
Below is the BFG KM1 next to the Toyo-
And the Toyo next to a Cooper ST in 255/85x16, probably the only all terrain in this size-
And below is a great comparison pic between the 265/75x16, 255/85x16 and the 285/75x16-
A smaller version of this tyre is the Interco Trxus, that measures 32.7x10.1x16.
http://www.intercotire.com/tires.php?id=11&g=1Hope that helps.