The Toyota Dophin is a small RV made in the 1980s.
They have a 4 cyclinder engine that got 14 mpg.
They are 16-18 feet long with a GVWR of 5000 lbs.
Freshwater tank was 17 gallons.
Grey and black tanks were each 19 gallons.
The sell used for about $3k-12k in 2022.
More info: https://itstillruns.com/first-ford-truck-made-5050496.html
Video clip of 1991 model inside and out: