That’s all nice, but mostly non-sequiturs of why there is ethanol in gasoline.
The real reason why ethanol was blended into gasoline was that the prior oxygenate, MTBE, was found to be responsible for contaminating ground water supplies where underground tanks leaked. So MTBE became a liability for refiners.
The EPA requires there to be an oxygenate additive in gasoline, so the next choice was ethanol. Modern closed-cycle EFI engines with O2 sensors in the exhaust stream don’t actually *need* any oxygenate additive in the fuel at all, but hey, we’re dealing with the environmentalists here who believe that without oxygenates that the LA basin would go back to the days of the 70’s, when you couldn’t see Mt. Wilson from Pasadena.
The reason why cars get worse mileage with ethanol in their fuel is that US automotive engineers can’t seem to remove their heads from their rectums and use the added octane boost to increase the compression ratio of the engine. Oddly enough, Ferrari was able to produce a 500HP high end sports car that gets better mileage on E85 than on pure gasoline.... just as any engineer who doesn’t have his head up his ass could do.
This cranial/rectal inversion that seems to run rampant in Detroit also seems to prevent them from delivering a small turbodiesel engine package that produces 50+ MPG vehicles as they have in Europe. Instead, they’re busy chasing utter twaddle like the Chevy Volt.
On diesels, the EPA’s particulate matter regulations have really done a number on trucks and heavy diesels the last few years. Some companies (including Mitsubishi) have actually halted production of trucks for the US market until the EPA got its regs finalized to a point where something could be designed to comply with it. Then the regs will change again.
I have always thought that MPG was a very poor measure of efficiency. There is nothing there to account for the load being moved. Under this system, a semi moving 80000lb of freight at 4MPG is less efficient than a Prius moving a 160lb guy at 40MPG. Is the Prius 10 times as efficient as the semi, or is the semi 50 times as efficient as the Prius.
Could this be why cars are delivered on trucks??