A truck delivers liquefied natural gas (LNG) to a refueling facility.
Filter changes

Fuel cleanliness is critical for LNG and CNG inspection systems. Maintenance for the ISX-G calls for oil and filter changes, including the fuel filter, at 30,000 miles or equivalent hours. The ISX-G uses both gas and diesel, injected separately. The diesel provides pilot ignition. It has spark plugs to help ignite the gas to sustain combustion. Other gas engines use glow plugs.

As we go to press, LNG was selling for the diesel energy-equivalent of less than $2.60 per gallon. Savings after all costs are about $1.00 to $1.50 per gallon on an energy-equivalent basis.

The lack of a delivery infrastructure may delay the broad acceptance of natural gas as a vehicle fuel. T. Boone Pickens advises us in his TV ads that natural gas is abundant, efficient, and it's ours. It doesn't have to be bought from countries that may not support America, but we still must get it into our vehicles.

The U.S. has an extensive natural gas delivery system, with pipelines bringing it to many homes and industries. But it still takes a significant capital investment, projected to be between $350,000 and $400,000 for a modest industrial-sized CNG compressor facility with related storage and dispensing equipment. Operating and maintenance costs can run from $0.15 to $0.35 per gallon equivalent. CNG must be compressed to less than 1% of what its volume is at standard atmospheric pressure, and must be stored at up to 3200 psi or more.

Another limiting factor could be weight. Vehicle tanks for CNG are heavier than for liquid fuel equivalents due to the high pressures they must contain. LNG is a cryogenic product with additional challenges. To reach its liquid state, the gas must be chilled and stored at -256° F. Vehicle fuel tanks and LNG storage tanks are insulated pressure vessels, more like thermos bottles than traditional fuel tanks. Specialized training and protective gear are required for LNG filling operations, but training for CNG takes five minutes or less.

With production still limited, refueling equipment isn't all that's costly about natural gas power. According to the Diesel Technology Forum (DTF), proponents of clean diesel engines, a Los Angeles drayage truck that might cost $110,000 can cost as much as $200,000 or more when equipped for LNG.

Research tax breaks

Before you think these costs are prohibitive, do some research. Federal and state grants, in addition to grants from private foundations, may be available in your area to partly or completely mitigate the costs associated with converting to natural gas, especially if you operate in an EPA Air Quality Non-Attainment Area. And many alternative fuel vehicles are exempt from the federal 12% excise tax.

Natural gas, liquid or compressed, is still not a perfect fuel. It has tiny quantities of contaminants that create different forms of pollution. Its exhaust contains traces of benzene, cyanide compounds, phenol, toluene, and 16 other toxic air contaminants, according to the DTF.

Handling LNG requires extensive training on refueling and maintenance, and even though LNG can be delivered and stored onsite, the initial investment is larger than for diesel tanks and pumps. But at $2.60 per gallon-equivalent or less, that benefit alone may outweigh all the disadvantages.

For more on converting to natural gas, visit Clean Energy at or the Natural Gas Vehicle Institute at

There are other reasons besides driver acceptance to convert to alternative fuels. Concrete producers, like most building and infrastructure contractors, must be aware of how the public views their businesses. Converting to alternative fuels and promoting the fact that you did so can greatly improve the perception of a producer as an environmentally responsible member of the local community.

In the environmentally conscious and very polluted Los Angeles basin, managers of the massive container operations at the ports of Los Angeles and Long Beach are converting to LNG fuel cartage tractors that pick up and deliver containers. In other cities, transit fleet managers are operating their busses using CNG.

Paul Abelson is a former director of the Technology and Maintenance Council of the American Trucking Association and is currently on the Board of Truck Writers of North America. E-mail