Here is a Hybrid of what's being discussed. I appreciate the numbers you gave, way above my knowledge level to figure out but totally understand it. But if you don't feel like totally pedaling but don't want to visit the gas station very often, maybe something like this is for you.
The trike is pretty much stock, meaning you could remove the engine and it would be back to normal. It's just below the legal stuff and I've used a NuVinci Drive
as a jack shaft to slow down the RPM's and also give me infinite gearing. Low gear is a max of 12 mph and high gear is a theoretical 46 mph (too fast for a bike). But after all that, I get about 137 mpg...Hybrid!