Alternative Fuels

As fuel prices rise and directives are given from the government and company executives to be more environmentally and operationally efficient, fleets have important decisions to make when incorporating new vehicles into their fleets. These new considerations have led fleets of all sizes across the country to include alternatively fueled vehicles, including those fueled by propane autogas.

Propane autogas refers to liquid petroleum gas (LPG) when it is used in an on-road engine. Propane autogas is non-toxic, colorless and virtually odorless. An identifying odor is added so it can be readily detected.

The third most common vehicle fuel in the United States, propane autogas fuels more than 270,000 buses, taxis, shuttles and light and medium duty truck and vans. Propane autogas reduces emissions while providing high performance and cost savings.

It is also a reliable, domestic resource, as nearly 90 percent of U.S. propane autogas supplies are produced in the United States.

In the past two years, more than a dozen new on-road platforms fueled by propane autogas have been developed with funding from the Propane Education & Research Council (PERC). Currently, more vehicle platforms are in development from Roush CleanTech, CleanFuel USA and Freightliner Custom Chassis Corporation.

Freightliner Custom Chassis manufactures premium chassis for the motorhome, delivery walk-in van and school bus and shuttle bus markets. Roush CleanTech and CleanFuel USA manufacture light and medium duty truck and van propane autogas systems.

Aftermarket conversion kits are available from manufacturers such as Alliance AutoGas, LandiRenzo, RGR Alternative Fuels, IMPCO, ICOM North America, and others.

Recently, the Indiana Department of Transportation (INDOT) and Austin, TX, rain gutter installation company Austin Gutter King, adopted propane autogas-fueled vehicles. While their fleets fall into different categories for size and usage, both have realized cost, performance and sustainability advantages from using these vehicles.


Business owner Gary Kulp has made his Austin Gutter King a sustainable home service company by building his company around a core of environmentally friendly initiatives. These include using wind-generated electricity to power its headquarters and reusing rainwater for everything from washing cars to flushing toilets.

It made sense to incorporate alternative fuels into the fleet. Austin Gutter King’s fleet of service vehicles includes three Ford F-150s and one Ford F-350 fueled by propane autogas.

“We consider ourselves to be the greenest home service company in America,” Kulp says. “We converted our vehicles to propane autogas because I wanted to lower fuel costs, but also support a sustainable, clean and domestic fuel source.”

Cost savings were also a factor for INDOT, which started exploring new ways to fuel its fleet of 2,300 light and medium duty trucks and vans in 2008 after gasoline prices rose.

“We were trying to figure out how to pay for fuel for the agency because we hadn’t budgeted enough for gasoline and diesel, and didn’t want to pass that cost along to taxpayers,” says Mark Ratliff, INDOT’s director of agency results and forecasting.

After attending seminars about various alternative fuels, INDOT determined propane autogas would best meet the agency’s needs and began converting nearly 600 of its vehicles to a bi-fuel system using gasoline and propane autogas. INDOT is currently in the process of converting the vehicles, which are used to transport highway maintenance crews, signal technicians and survey crews to job sites and projects.

“We had a greater opportunity with propane autogas because of the lower costs than other fuel technologies,” said Joe Rudolph, INDOT’s director of technical services.

Cost Savings

Due to the large volume of propane autogas consumed by INDOT’s sizeable fleet, the agency has been able to negotiate a fuel cost that saves significant taxpayer dollars each month. Based on INDOT initial figures, savings could exceed $1 million on an annual basis.

Smaller fleets also can benefit from the lower cost of propane autogas. For the last 30 years, the cost of propane autogas has been, on average, 30 percent less than the cost of gasoline. Austin Gutter King’s Kulp says he saves approximately 40 percent on propane autogas compared with the diesel he buys for his other fleet vehicles.

Additional savings comes from a federal tax credit for the use of propane autogas. Fleets can claim 50-cents-per-gallon on fuel purchases through December 31, 2011.

Vehicles fueled by propane autogas also have saved both Austin Gutter King and INDOT money through reduced maintenance costs. Propane autogas burns hotter, cleaner and more efficiently than gasoline and diesel, resulting in reduced wear to engines and longer engine life.

“We have seen significantly reduced maintenance costs because we don’t have to change the oil nearly as often since propane autogas burns so much cleaner,” says Kulp. “We expect the engines to last twice as long because there are fewer hydrocarbons in the fuel. We’re expecting to get about 300,000 miles out of those engines.”

Manufacturers are able to calibrate engines fueled by propane autogas for increased efficiency and higher combustion so the vehicles provide the same horsepower, torque, and towing capacity as gasoline-fueled versions of the same models, while emitting fewer greenhouse gas emissions.

INDOT has not experienced any difference related to the performance of its converted trucks, which is being measured as a part of the contract for its conversion to test the amount of torque and rear wheel horsepower produced.

“It feels great to know that there’s a viable option out there that isn’t using gasoline,” says Jason Jones, INDOT’s director of highway maintenance. “It’s great to drive a vehicle fueled by propane autogas. You can’t tell any difference.”

“It’s just like a regular truck,” agrees Kulp. “I’ve got a 60-gallon tank in the bed of the truck, and I like it because it moves the weight forward and allows me to tow more because I no longer have the 35-gallon gas tank at the very rear of the vehicle.”


Ease of refueling has accelerated the use of vehicles fueled by propane autogas among fleets of various sizes.

Many fleets are realizing the advantages of installing an on-site refueling dispenser, which is compact and easy to install. The cost of installing a propane autogas refueling station is comparable to the cost of installing a gasoline or diesel refueling station.

Propane autogas providers can help fleet managers select the best on-site refueling option, and coordinate ongoing delivery of propane autogas.

Fleets also can refuel off-site at one of thousands of refueling stations across the United States. There are more propane autogas refueling stations in the country than for any other alternative fuel, including one in every state, according to the Energy Department’s Alternative Fuels and Advanced Vehicle Data Center.

INDOT and Austin Gutter King each have installed on-site dispensing for their fleets, but on very different scales.

INDOT has 115 refueling sites set up across the state of Indiana, spaced about 30 miles apart, which were installed by a state contractor. Each site has a 1,000-gallon tank with a dispenser accessible to drivers 24 hours a day. A fuel card issued to each driver provides access to the facility.

The state has contracts with various regional propane autogas providers to facilitate fuel deliveries. As more of the INDOT vehicles are converted to propane autogas, INDOT anticipates installing larger tanks at some of the refueling sites.

Austin Gutter King has a 500-gallon tank at its headquarters to refuel vehicles. The infrastructure was installed by its propane autogas provider, which also facilitates fuel delivery.

Drivers in both fleets have completed safety training sessions to learn the proper procedures for refueling vehicles.

“Our propane autogas provider conducted training to refuel vehicles, which is a relatively simple process - just as simple as gasoline,” Kulp says.


Vehicles fueled by propane autogas not only provide high performance, cost savings and easy refueling, but also reduce emissions. On average, fleet vehicles fueled by propane autogas emit 12 percent less carbon dioxide, about 20 percent less nitrogen oxide and up to 60 percent less carbon monoxide than gasoline-fueled vehicles.

“We promote our ‘green’ trucks to the Austin community as an example of an environmentally responsible organization,” Kulp says. “Our Roush CleanTech vehicles are a part of that. I haven’t had any surprises with the vehicles. It’s a seamless system.”

“We can only benefit from more people converting to propane autogas,” Rudolph of INDOT adds. “This goes beyond saving the state and taxpayers money. It’s about using a domestic product that is made and used in the United States.”

Fleet managers interested in vehicles fueled by propane autogas should contact their fleet dealers or vehicle manufacturers. For more information about PERC and vehicles fueled by propane autogas, visit, or contact local propane autogas providers.

Steve Wayne is the chief commercial officer for the Propane Education & Research (PERC). It was authorized by the U.S. Congress with the passage of Public Law 104-284, the Propane Education and Research Act, signed into law on October 11, 1996. PERC’s mission is to promote the safe, efficient use of odorized propane gas as a preferred energy source through research and development, training and safety initiatives.