INDIANAPOLIS, Ind. — Even with a markup of 40% compared to the cost of diesel-powered tractors, Giant Eagle’s compressed natural gas (CNG)-powered Volvos are delivering a substantial savings.

Mike Lickert, fleet manager with Pittsburgh, Pa.-based Giant Eagle, discussed his company’s CNG trucking program at the Green Truck Summit.

The company took delivery of its first CNG-powered tractors in 2011, which included the first 10 CNG-powered Volvo trucks ever built. It also opened a $1-million CNG fuelling station.

Initially, the trucks came powered by the 8.9-litre Cummins Westport spark-ignited engine, but in the fourth quarter of 2013 Giant Eagle added 40 trucks with the 11.9-litre ISX12 G. That brings the CNG fleet to 61 trucks, plus a yard tractor and natural gas-powered reefer.

Lickert said the fuel savings have met expectations, even though at 4.6 miles per gallon, the trucks achieve worse mileage than the diesels (5.7 mpg). The fuel costs per mile are 42 cents for the CNG trucks and 70 cents for the diesels, Lickert noted.

Among the lessons learned along the way are that the belief natural gas trucks will extend oil life is a myth, Lickert said.

“Right now, we have to change the oil more often than with the diesels,” he said. “We’re working with a major oil manufacturer to extend that and make it diesel-like.”

But he also said the belief that maintenance costs will be higher is also a myth. Lickert said the company budgeted for an extra penny per mile in maintenance-related expenses, but that hasn’t been necessary.

“What you’re spending on spark plugs, you’re saving on emissions controls,” he said, noting these trucks are free of SCR and its associated problems.

Lickert was charged with developing a natural gas trucking program after a company executive returned from a trip to India and noticed the trucks there were powered by natural gas. In addition to fuel savings, Lickert said the trucks are quiet to operate and the newer vehicles with the ISX12 G (400 hp/1,400 lb.-ft. torque) provide diesel-like performance.