Cars I've towed with:
Infiniti G35 coupe, 6 speed - double-place motorcycle trailer fully loaded plus trunk and back seat floor fully loaded plus 2 adults, 1 child, and 2 dogs. Still got 18mpg and power was not an issue.
Hyundai Sonata (4cyl) - same double-place motorcycle trailer fully loaded plus trunk and back seat fully loaded plus 2 adults and sometimes 1 dog. Again, 18mpg, but car was sluggish.
- 5x8 trailer with Grizzly on it, trunk full. 17-18mpg, car was sluggish.
- 14 ft boat with motor, trunk full and 2 adults. 18mpg, car handled the boat very well.
- 16 ft boat with motor, trunk full and 3 adults. 17mpg, car was sluggish.
Current tow vehicle is basically the same as the 4Runner in question:
Toyota Tacoma TRD Off Road - Same 2 motorcycle trailer as above, truck bad and back seat full, 17mpg. Don't even know the trailer is back there.
- Same ATV trailer as above, truck loaded, 17mpg. Trailer is noticeable but a breeze to tow.
- 20 ft pontoon boat, truck loaded, 4 adults, 2 dogs, 15-17mpg. Truck is sluggish.
One ATV behind a truck - any truck on the market - not a problem.