As a biofuel, ethanol is relatively easy to make, but it has a lower energy density than gasoline and can't be transported through existing pipelines designed for petroleum fuels.

Diesel fuel has a higher energy density than gasoline, so a diesel engine gets better mileage.

The next goal is to find a similarly efficient second catalyst to transform the by-products into an energy-dense fuel like methanol to give gasoline a run for its money.