I've pulled my 'tent on a trailer' several thousand miles. It weighs on the order of 400 to 450 lbs. As others have said, stopping is primary concern. I can tell when it's attached when it comes to stopping. What others haven't mentioned, and it's a big difference from your 1800, is power at interstate speeds. At 70+ pulling 400# you will not have the reserve torque to pass a semi like you had with the 1800. Gas mileage will take a hit, especially if the trailer isn't aerodynamic. If you're thinking about pulling 500# plus, and you get into a headwind going uphill, and want to travel 70+, you very well may get frustrated. Plan to do a lot of driving in 5th gear, and maybe even 4th. Cruising on the level with no headwind you'll do fine in 6th.