Towing 5200lbs with a 06 Nissan Pathfinder

Note that your best towing will be in 3rd gear, with the engine churning at 3500rpms or more depending on what speed you want to maintain;

Not my idea of a pleasant towing experience, but hey that's me.

Sorry for your anguish over not reaching towing capacity due to payload limitations, but that is how manufactures sell product. I'm constantly amazed at people who I consider gifted intellectually, get hooked on tow capacity when researching a vehicle for towing an RV.