If he can get a
1960 Lincoln Continental to pull 100 mpg, he'll start a revolution.
Our family had a '64 and '65 Continental and those damn things weighed 6,000 lbs.
One wonders if there isn't some limit in terms of available work per unit of fuel. Getting 90% efficiency out of that fuel might lead to 100 mpg for a large car but that might be on the fanciful side.