Are they LT235/85R16 'E' rated tires (OEM on 6000# axles) or the updrade 7000# axles with LT235/85R16 'G' Rated tires?
Seeing as how rig was barely used they are probably original tires. (Date code on inside sidewall-----4 digit DOT code XXXX. 1st two numbers (XX) are week that tires were made---2nd set of numbers (XX) is the year 3706=37th week of 2006)
Tires that OLD need to be replaced.
'E' rated (6000# axles)..........lots of good options
'G' rated (7000# upgrade axles)......not lot of options. Goodyear G614's