The North American division of Fiat Chrysler Automobiles (FCA) plans is spending $40 million to convert 179 tractors in its private fleet operation hauling parts to its Detroit assembly plants to run on compressed natural gas (CNG).

FCA US LLC also spent $1.8 million to upgrade the 36,000 sq. ft. shop handling maintenance for FCA Transport, its private fleet, to safely work on CNG trucks, along with another $5 million on-site CNG fueling station, designed and built by TruStar Energy.

Steve Beahm, senior VP-supply chain management for FCA North America, said prior to this changeover, the FCA Transport fleet used nearly 2.6 million gallons of diesel fuel annually while accruing some 16 million miles to deliver parts from suppliers and FCA U.S. component facilities to its assembly plants in Detroit.

As a result of its shift to CNG, the company expects to experience net fuel cost savings of about 35% per year, he noted.

“Our transition to CNG reflects the way FCA US attempts to balance our search for profitability with social responsibility and community development, including environmental stewardship,” Beahm added. “This project was a win-win-win – it offered a solid business case, clear environmental benefits and an opportunity to invest in our Detroit facility and workforce.”

The CNG conversion effort also represents the culmination of two years of research and planning, an extensive pilot program of CNG trucks and ongoing training of more than 6,000 hours, Marty DiFiore, head of FCA Transport and Auto Transport Services, noted in a statement.

“FCA Transport drivers and mechanics participated in extensive hands-on training to prepare them to drive, fuel, and maintain the new trucks,” he pointed out. “[That training] included maintenance, repair and operating courses taught by Cummins, Allison Transmission, Agility Fuel Systems and FCA’s own in-house trainers.”