HOUSTON, Texas — The environmental and economic benefits of running natural gas-powered Class 8 tractors is intriguing, but the payback isn’t yet quick enough to justify the substantial capital investment.

That was the message from Ted Phillips, vice-president of fleet operations with Dr. Pepper Snapple Group, when discussing his company’s natural gas experience at the Natural Gas Fleet Vehicles North American Congress. Phillips approached the topic from the perspective of manager of a private fleet for a publicly traded company, where quick returns are demanded by shareholders. Still, while the company won’t be replacing its fleet with natural gas vehicles right away, Phillips still predicted that by 2017, 20% of the company’s fleet will be powered by natural gas.

Dr. Pepper Snapple Group is the 12th largest private fleet in the US, operating 2,800 power units in its medium- and heavy-duty truck fleet. It has experimented with hybrids and electric vehicles without achieving an acceptable return on investment.

The company ran a trial with CNG-powered tractors and concluded a payback would be achieved in about four years. As a private fleet, Phillips acknowledged he must compete for capital dollars against other departments and a four-year payback was a tough sell. Heading into the trial, Phillips said the fleet targeted a payback of less than one-and-a-half to two years.

During its CNG trial, Phillips said the fleet had to alter its routes to fuel up, due to the lack of fuelling sites. Stacking the CNG tanks behind the cab was problematic for the beverage hauler, because it spec’s short wheelbases and keeps a narrow gap between tractor and trailers so it can maneuver in tight spaces, such as convenience store parking lots.

Dr. Pepper Snapple Group pulls heavy loads and struggled to get up the hills with the ISL9 G engine. It also saw fuel mileage decrease 10%. Despite the drawbacks, Phillips is still a believer in the technology. He said the fleet will closely watch the market in hopes that increased demand and higher production volumes will bring costs down and lead to the construction of more fuelling sites.

“That should pave the way for corporate support to go with natural gas,” he concluded.