But it ain't gonna be an 100% _overall_ increase in efficiency.
The first question in any efficiency improvement claim is "where was the inefficiency in the first place?"
The hard fact of life is that most of the fuel is _already_ being burned in a well tuned vehicle's cylinders.
GM claims they can improve fuel efficiency by 15% with better combustion but that engine won't be out for at least 6 years.
So the real improvement in any after market enhanced combustion approach to improving efficiency is less than 15%, probably much less.
The "mechanical engineer" on the videoclip was flat out lying about the 70 mpg.
Back in the 70s GM had a way of dealing with scammers and crackpots: They told them to bring their vehicle on down to their test track and allow the attendant to weigh the vegicle. After so many laps they'ld weigh the vehicle again.
The attendant didn't have to talk to many frauds because the frauds knew better than to allow anyone to weigh their vehicles and count laps.
There already is a $60 invention that will vastly improve miles/ gallon. It was invented over 150 years ago: