What is the maximum tire size you can install on a standart 15x5  samurai wheel ( rim)
Can you fit a 235/75 R15?
Thanks guys!!

The 235/75 R15 will go on there without an issue, and it will fit on a Samurai with only some light bumper trimming.  Let us know how she looks after you get the new tread. 

I have a 31/10.50/R15 tire on a stock rim I use it as my spare on the back.

If you are wanting to stay with manufactures recommendations then here is an example.  Go to this link then on the right click the "more" button.  It will show you what rim size range they recommend by tire size.  I would bet the manufacturers know a fair bit about rubber.  http://www.bfgoodrichtires.com/tire-selector/name/mud-terrain-t-a-km2-tires

Fair enough, but until recently I thought it was okay to run 285/75/16s on stock chevy truck wheels...guess not.  The rim is 1" under the specified range...but it's taken my father and I's trucks over 200,000 miles safely.  DIdn't know we were "not within spec" until recently.

Purely a recommendation.  I am sure Suzuki would not recommend putting a lift on a sidekick, but we do it anyway.  This chart is more of a starting point for The German's quest for knowledge.  My old set of tires was 235's on an 8" rim which ran fine, but according to the chart was too narrow for the rims.  Heck I don't know what the right answers are forsure, just figure the boys making the things know way more than I do.