Oh I agree about the car or family vehicle being turn key ready to go.
On the dead inventors, think about what and who, more importantly they stood against with these inventions. They were bought out or sabotaged. These things did work but like many of us they lacked the finances to make it happen.
When I started this thread I didn’t realize that most of these individuals experimenting with the hot air induction or fuel vapor system got it to work for a short period of time. The leaded gasoline, and the additives in fuel today eventually render this vaporization process useless and the mileage reverts back. Big oil companies bought the patents to these “supercarbs”. The early success was on pure gas or white gas as well.
It’s all a what if,food for thought, and have you done it?? maybe a fun project on the said stationary machines, lawnmowers, and snow blowers.