Advancements in alternative fuels are continuous. For example, butanol can power any automobile in the same way as gasoline. It produces more power than ethanol and almost as much power as gasoline. It can be made from a great variety of plant materials, from pulp waste from paper mills to whey, a waste product from cheese-making.

Hydrogen fuel cells also offer promise. Such vehicles “were a hot topic in the recent past and there continues to be investment in the light-duty sector,” Eichberger says. “However, most of the anticipated growth in this sector comes from the medium- and heavy-duty vehicle space where power-to-weight ratio of the fuel supply system plays in its favor. Hydrogen allows heavier vehicles to be converted to zero emissions; the biggest challenge remains infrastructure for refueling. For return to base fleets, refueling is not much of a challenge, which is why this could yield positive opportunities to fleet conversions.”