By the Propane Education & Research Council

The future for fleet vehicles of every make, model and class is becoming a deeper shade of green. Not only are companies facing state and local government regulations to meet lower emissions and tighter Corporate Average Fuel Economy (CAFE) standards, but pressure from communities and customers is requiring many companies to consider switching their fleets to use alternative fuels. And with the growing number of options for alternative fuels, fleets, fuel marketers and retailers need to make an informed decision on what fuel to commit to in order to meet their needs.

One fuel that continues to stand out for not only having an established reputation as a reliable alternative fuel with the lowest total cost-of-ownership, but for also continuing to advance clean energy technology, is propane autogas.

Over the past four decades, propane autogas has emerged as a proven alternative fuel, with more than 200,000 propane autogas vehicles on the road in the United States. Propane autogas is recognized as a solution for fleets seeking reduced emissions, with the fuel providing a range of environmental benefits. Along with reducing nitrogen oxide (NOx), greenhouse gas, and even particulate matter emissions, propane is non-toxic and does not contaminate air, land or water resources. Combine this with the fact that today’s liquid propane autogas fuel systems provide vehicles with power and performance that is comparable to other fuels, and it’s easy to see why marketers, retailers and their customers are taking notice.

Two recent innovations with propane autogas also ensure that the fuel will continue to have a place in the clean energy conversation: the announcement of ultra-low NOx engines and the continued development of renewable, biologically-sourced propane.


Ultra-low NOx Engine Innovation

In 2018, not one, but two original equipment manufacturers (OEMs) introduced ultra-low NOx propane autogas engines that are 90 percent cleaner than mandated Environmental Protection Agency standards and certified to the optional ultra-low NOx emissions standard as defined by the California Air Resources Board (CARB) for heavy-duty engines with .02 grams per brake horsepower-hour. The new engine technology, available from Roush CleanTech and Greenkraft, Inc., is classified as near-zero emissions and has moved propane autogas even closer to achieving zero emissions levels.

This technology also alleviates one of the pain points of traditional fuel combustion. By reducing NOx emissions to near-zero levels, it shows that propane autogas can help improve air quality. When used in school buses and public transit vehicles—two of the prime uses of these engines—it can reduce concerns about breathing-related and other health issues associated with exposure to NOx emissions, too.


Renewable Propane is Redefining what it Means to Have Clean, Accessible Fuel

In addition to the ultra-low NOx propane autogas engines, renewable propane is changing the standards of what it means to be a clean fuel. Renewable propane is a byproduct of the production processes for renewable diesel and jet fuel, which converts plant and vegetable oils, waste greases and animal fat into fuel. In fact, several U.S.-based refineries are already capable of producing renewable propane.

Because renewable propane’s chemical structure and physical properties are the same as current propane production, renewable propane behaves in the same way as propane autogas, providing fleet owners the same performance and reliability they depend on. At the point of combustion, renewable propane is carbon neutral, meaning no new carbon is added to the atmosphere during combustion. Renewable propane produces fewer lifecycle carbon dioxide emissions than traditionally sourced propane.

As more research and attention is given to what is possible for renewable energy across the U.S. and the world, this puts propane autogas at the forefront of the conversation among solar, wind and other biofuels. Additionally, as renewable technology gains traction beyond the on-road market, fuel marketers and retailers can see even greater long-term benefits. It’s predicted that renewable propane will be capable of supplying most of the world’s propane needs by 2040.

These innovations are tremendously important, as the future of engine fuels continues to aggressively move to zero emissions.

These recent improvements and those that are in development are possible thanks to the strong foundation propane autogas has established in the transportation industry over the last four decades. With these new innovations, propane autogas continues to set itself apart from other alternative fuels as a proven, clean, domestic, and affordable fuel option for both fuel marketers and retailers, and the fleet customers they service.


The Propane Education & Research Council is a nonprofit that provides leading propane safety and training programs and invests in research and development of new propane-powered technologies. PERC is operated and funded by the propane industry. For more information, visit To learn more about propane autogas vehicles, visit