OK I acknowledge the reason for your ignorance of the issue. The
designation of vehicle type is on the manufacturer's Certificate of
Origin that you present to DMV the first time the vehicle enters the
title system (hence my reference to Canada and their US market).
In the case of my dune buggy, I was the manufacturer and I got to
decide what to call it as long as it met the DMV guideline at the
time. A car was inspected, a truck wasn't so the trick to get a dune
buggy on the road was to have a little bed in the back and title it as
a truck.
In the case of these little car frames with truck or SUV bodies, the
manufacturer decides what to call them, within certain limits. If it
has an open bed it will be a 1/2 ton pickup tho. It is when it has a
metal fully enclosed bed that it can be a car, a truck or a utility
vehicle. My Suburban was titled as a car and it had the Chevy "C" body
truck chassis. My "Jeepster" (72 Jeep Commando) was 1000 pounds
lighter and it was a utility vehicle. If it was ordered without the
full top, it was a truck.
The Ford 1/2 ton has a towing capacity from 50% to 100% (depending on engine) greater than the
4Runner. I wouldn't put the 4Runner in the same category. Maybe closer to the Tacoma.