WATERBURY – Could the propane you use to cook your meals or dry your clothes also be the best fuel for school buses? The answer from All-Star Transportation, and many others, is yes.

All-Star Transportation, which provides service to more than 35,000 students daily during the school year in Fairfield, Litchfield and New Haven counties, is among those forward-thinking companies nationwide that are deploying propane-fueled buses to replace diesel buses. All-Star currently has 136 propane vehicles in its fleet with plans to add more in the future.

“We have had excellent results with our propane buses and that is why we are aggressively adding more to our fleet,” says Leslie Sheldon, operations manager for All-Star and president of the Connecticut School Transportation Association (COSTA).

“There are so many benefits to propane buses. For instance, the maintenance costs for propane buses are lower compared to diesel buses, and that’s no small consideration given today’s tight education budgets,” Sheldon adds.

Propane’s low carbon and low oil contamination also contribute to longer engine life. And compared to vehicles fueled with diesel and gasoline, propane vehicles can produce lower amounts of harmful tailpipe emissions, depending upon the age of the vehicle and other factors. Propane also performs well in cold weather climates like Connecticut because the fuel’s mixture is completely gaseous. This makes it possible for propane vehicles to avoid the cold-start issues associated with diesel and gasoline.

“Propane buses also are much quieter than diesel buses,” says Sheldon, “and that’s a great benefit to drivers. A quieter bus makes it easier for our drivers to hear what’s happening in the back of the bus.”

There are now more than 143,000 propane vehicles on the road in the United States, according to the Propane Education and Research Council. Most are used in fleets, such as shuttles, police vehicles and school buses. The U.S. Department of Energy recently studied the use of propane school bus fleets in Virginia and Texas, concluding that the fleets had no “significant technical or management hurdles associated with the deployment of propane buses, and most of them are exploring ways to expand their use of propane in the future.”

The overwhelming majority of the nation’s 480,000 school buses use diesel fuel, leading some to voice concerns over the negative environmental impact caused by the exhaust from these vehicles. Others argue that low-sulfur diesel fuel and newer engines under development will eventually ease environmental concerns and ensure diesel’s continuing domination of the school bus market.

The U.S. Environmental Protection Agency has become engaged with propane buses through its Clean School Bus USA. It’s a public-private partnership that focuses on reducing children’s exposure to harmful diesel exhaust by limiting school bus idling, implementing pollution reduction technologies, improving route logistics and switching to clean fuels.

Those who favor propane note that it is less harmful to the environment compared to traditional fossil fuels. Burning propane reduces greenhouse gas emissions by 22 percent compared to gasoline-powered buses and 6 percent compared to diesel, according to the Propane Education & Research Council, an organization funded by the propane industry.

Propane vehicles are similar to their gasoline counterparts with regard to power, acceleration, cruising speed and driving range. A gallon of propane has 27 percent less energy than a gallon of gasoline, according to the Department of Energy. However, propane has a higher octane rating than gasoline (104-112 compared to 87-92 for gasoline), and the Energy Department notes that some manufacturers are developing engines to take advantage of this higher rating, leading to improved performance and fuel economy.

“At All-Star Transportation we are convinced that propane is the best option for the future, and it is our goal to convert our entire fleet to propane in the years ahead to lessen our impact on the environment, reduce fuel costs and make our buses safer,” Sheldon says.