The Digest’s 2018 Visual Guide to the economics, politics of renewable fuels

If you’ve wondered why E85 doesn’t generate a lot of enthusiasm among fuel buyers, this graphic will help. Here. we look at E85 prices and the energy value. Now, E85 engines are modified to accept ethanol, but they are almost invariably not modified to optimize for ethanol and fully utilize its properties.

Consider an E85 engine to be something like eating grass. When you look at cows, you know there’s energy value in grass, but you can eat it and you never seem to get much out of it. That’s because our bodies are built to tolerate grass, but we don’t have a digestive system that is optimized for it. Car makers could tune engines to optimize for ethanol, but they don’t.

So, drivers are left with energy values, and they operate in retail markets rather than in the weird world of refinery economics or in wholesale markets. And, according to our friends at the Renewable Fuels Association and their e85prices.com site, the US average E85 price is $1.98 and the average E10 price is 2.48.

That means, drivers are getting a 20 percent price discount for R85, but the energy value is around 25 percent lower. In other words, you pay more to drive E85 on a per-mile basis.