Same with ethanol gas. If not for the corn subsidies, it wouldn't be cheaper. Also much more gas is burned growing/harvesting the corn and electrical powering the process than is saved in emissions (there was a great piece on HN of this some time ago), so it's a net negative to the environment. It's so dumb it hurts, but Iowa is an early presidential election state, so good luck finding someone who will go in and tell those early voters that they're gonna slow the gravy train...

The actual reason we stay on ethanol as a fuel additive is not about saving the planet: It's simply a good octane booster for the kinds of reliable octane you need in modern engines. Before, we had leaded gas which is bad, then MTBE which kept poisoning water tables.

In contrast, using 15% ethanol uses 15% less gas at a time when we were desperately trying to not be held by the balls by the middle east gas sellers, it's trivial to produce at scale, it was a simple handout to corn growers, which the US cares deeply about, and refineries didn't mind that it reduced the energy density of fuel by a couple percent, requiring you buy more gas for the same amount of energy, and it would never end up with a 60 minutes special about how it has been poisoning all of us for decades. We should have been using it the whole damn time.

thank you, this is interesting and a great point for further research