I have 2008 Jayco17c ex-port that came with ST185 13 D tires. I replaced them with ST205 14 R tires with a 1740 lb rating. The 185 13 D tire did not exist at any dealer and had to be ordered if replaced. The 185 13 R cousin is rated 1,440 lb, too little for the 3,500 Gross weight camper, and throws radial treads off tire bodies within about 2,000 miles of interstate driving so I went to the larger tire after much, much research. Jayco is using the 205 tire on similar campers now, I've observed. Brand wise the tire I specified was Carlyle after research.