Looking at Propane Autogas for Transit Fleets

As the government continues to develop new standards for vehicle emissions, fleet managers are looking to incorporate vehicles that meet sustainability requirements while maintaining organizational cost and performance goals.

One option growing in popularity is incorporating buses, shuttles and vans fueled by propane autogas into fleets. New models feature the latest in propane autogas technology, and successfully meet cost, performance and sustainability expectations, while offering a viable alternative to conventionally fueled vehicles.

Mammoth Cave National Park uses buses fueled by propane autogas to transport more than 200,000 visitors annually. Because of the success the park has already seen, it recently bought four new Blue Bird Propane-Powered Vision school buses to replace aging buses in its fleet through a grant from the Energy Department and facilitated by the Kentucky Clean Fuels Coalition.

Sustainable, high-performing solution

The cost, performance and sustainability attributes are a few of the reasons that Mammoth Cave National Park converted its entire fleet of six buses from gasoline to propane autogas more than a decade ago.

Mammoth Cave’s buses join more than 270,000 on-road vehicles today in the United States, according to the Energy Department, running on propane autogas, the nation’s third-most-common vehicle fuel after gasoline and diesel.

The park’s concessionaire, Forever Resorts, owns, operates and maintains the buses. The buses travel up to 10 hours a day for a combined 475 miles during the park’s busy season.

“Fueling our buses with propane autogas matches Mammoth Cave’s mission to be an environmental leader and employ sustainable practices,” says Mammoth Cave National Park Superintendent Pat Reed. “The buses allow us to transport visitors while reducing our carbon footprint.”

Propane-autogas-fueled vehicles emit 12 percent less carbon dioxide, about 20 percent less nitrogen oxide, and up to 60 percent less carbon monoxide than gasoline-fueled vehicles, ultimately reducing greenhouse gas emissions by up to 25 percent.

The California Air Resources Board (CARB) has granted certification approval for many buses, vans and shuttles fueled by propane autogas. The U.S. EPA also has certified these vehicles.

High performance with reduced maintenance

Along with sustainability comes high performance. Operators of vehicles fueled by propane autogas experience the same horsepower and torque as gasoline- and diesel-fueled engines.

“The performance is exactly the same as a gasoline- or diesel-fueled bus; there is immediate acceleration and lots of power,” Davis says. “If you drive a bus, you would never know it didn’t run on gasoline.”

Mammoth Cave services the buses through certified mechanics who have been trained to perform maintenance on the buses.

“Our engines are getting more years of service with propane autogas,” Davis says.

Propane autogas also burns cleaner in engines than gasoline and diesel, which traditionally results in reduced maintenance costs throughout the life of a vehicle, and extended engine life. While vehicles fueled by propane autogas may have a purchase price that can be up to $4,000 to $12,000 more than that of traditional gasoline- and diesel-fueled vehicles, these costs can be offset by the reduced maintenance costs and less expensive propane autogas fuel.

As a practice, the park continues to change the buses’ oil approximately every 3,500 miles, but technicians have noted that the cleaner-burning fuel does not require oil changes as frequently as conventional fuels.

Implementation that can curb costs

Federal and state incentives support adoption of buses, shuttles and vans fueled by propane autogas and create new opportunities in the market.

The federal government and many states offer programs encouraging the use of alternative fuels, with most states offering at least one incentive. This includes a propane autogas fuel tax credit of 50 cents per gallon through Dec. 31, 2011, as part of the Tax Relief, Unemployment Insurance Reauthorization, and Job Creation Act of 2010.