My Jeep's original towing capacity was 3500lbs. Tongue weight limit was originally 350lbs and Jeep load limit was reduced by tongue weight lb for lb.
But my Jeep is far from stock and the AEV suspension has proven itself excellent at carrying weight. Still, with even a fairly disciplined, perhaps sparse loading (and who would want to sparsely load a Karavan!) an all in weight of 4500lbs, maybe more, with tongue weight @ 12%-15% between 450lbs and 675lbs I think its too much for the Jeep.
That 6000lb capacity would make the Karavan a middlin' load for your 4Runner.
JPK
But my Jeep is far from stock and the AEV suspension has proven itself excellent at carrying weight. Still, with even a fairly disciplined, perhaps sparse loading (and who would want to sparsely load a Karavan!) an all in weight of 4500lbs, maybe more, with tongue weight @ 12%-15% between 450lbs and 675lbs I think its too much for the Jeep.
That 6000lb capacity would make the Karavan a middlin' load for your 4Runner.
JPK