[svedspx]

I have the Hankook RF10 E load in stock 18 size and I had the same problem. Front end felt loose and wind had more effect than I expected. Took me a couple of weeks to figure it out. I ended up changing the pressures to 38 front 39 rear when unloaded and 39 front and 50 rear when the fifth wheel is in tow. My pin weight is lighter (1300#) than yours. When weighing the set up I found that only 40# was transfered to the front axle so I keep the front pressure about the same, maybe a pound or two more. Others have found that no weight is transfered to the front when the fifth wheel is loaded. Keeping the front pressures lower was the key for me to get about the same handling as the old Pmetric tires. Good luck.