CHICAGO -- The GO Group, a major airport shuttle provider, is seeing more and more of its member fleets go green. GO companies serving San Francisco International, Seattle-Tacoma International, Milwaukee's General Mitchell International, Dallas-Ft. Worth and Puerto Rico's Luis Munoz Marin International airports are converting all or part of their fleets to alternative fuels – either compressed natural gas (CNG) or propane.  

Moreover, GO companies in Los Angeles (serving all southern California airports) and Chicago (serving Midway and O'Hare) are in the process of greening their fleets.

Companies that convert to alternative fuels can earn a 50 cents-per-gallon tax credit as well other incentives from local government and the airports.

GO Shuttle Express in Seattle, which has 43 propane-fueled vehicles, began the conversion process in January 2011 and has 20 more systems to install. J. R. Rowley, president of GO Shuttle Express, said the fuel savings represent around $2 per gallon. Maintenance costs, however, have been slightly higher because of the learning curve.

In San Francisco, GO Lorries has converted 16 vans to CNG, with another 28 to be retrofitted for CNG by May. "The conversions are expensive," said GO Lorries President Julio Bonilla, "but the fuel savings mitigate the cost."

As of December, GO Riteway Transportation Group in Milwaukee had moved 21 of its 500-vehicle fleet to propane, seeing $7,000 in fuel savings since October. Jason Ebert, fleet and facilities coordinator, said the maintenance costs are lower since oil changes can now be performed every 7,000 rather than every 5,000 miles. 

Ebert said one reason GO Riteway opted for propane is that it is 90 percent as efficient as gasoline, which allows for a greater vehicle range than CNG, which is only 31 percent efficient.  Also, the cost of a propane conversion is one third less than the cost of a CNG conversion.