Tow capacity ratings are mythical advertising numbers. They are based on pulling a flat bed trailer (little to no wind resistance), with a 150 lb driver, who is alone and has no cargo.
A travel trailer is a completely different animal. It has a lot of wind resistance, and, the driver is rarely alone, or without cargo of some kind.
Tow vehicles have multiple ratings that must be observed. In addition to tow capacity, you need to watch payload (cargo carrying capacity), gross weight vehicle weight rating (GVWR), gross combined vehicle weight rating (GCVWR), and hitch receiver rating.
GVWR is max weight rating on the tow vehicle's frame, suspension, power train, drive train, tires, and brakes
Payload is the difference between what the vehicle actually weighs, and it's GVWR. If it weighs 5500 and has 7000 GVWR- the payload would be 1500 lbs. That is weight capacity for fuel, occupants, cargo, WD hitch, and trailer tongue weight, combined.
GCVWR is max weight rating for tow vehicle and trailer combined. This includes everything and every body, in or on both, tow vehicle and trailer.
Hitch receiver rating is amount of weight the receiver is rated to carry, with or without weight distribution.
If you're planning to purchase both, tow vehicle and trailer, I would suggest you select the trailer, then shop for a tow vehicle that has the capacity ratings (in all areas) to support the trailer, cargo, and planned occupant weights. Keep in mind, towing at max weight is unpleasant. You may want some cushion in the ratings.
6500 - 6700 lbs loaded trailer will need 900 lbs (+ or - 50 lbs) out of your available payload.
When you shop for the tow vehicle, check it's payload first. Then deduct for passengers and cargo, and see if there is still room for your loaded tongue weight.
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