A fleet manager plans to install additional copies of an aftermarket dual-fuel diesel-and-natural-gas system following a successful 18-month test.

Bestway Express Inc., a dry freight carrier based in Vincennes, Ind., partnered with the Dual Flex+ system’s maker, D2G Inc., in a demonstration program for the last eighteen months, converting several of Bestway’s trucks to burn compressed natural gas with diesel fuel.  

“The D2G system has sustained outstanding results,” Will McCormick, Bestway’s director of maintenance, said in a statement. “We are running on 60%-70% natural gas without any performance or maintenance issues.

“We have stressed the duty cycle limits of these trucks, running them 800 miles and 24 hours per day and they’ve held up well,” McCormick said. “We are very impressed by D2G system and we will convert as much of our fleet as we can.”

The expansion comes as Bestway Express prepares to open its private and public compressed natural gas station in Vincennes.

The new Dual Flex+ system is the result of dual-fuel fumigation technology proven in thousands of standby generators and large off-road vehicles for over 20 years, said D2G’s founder, Elio Muller. Dual Flex+ has been developed around modern truck engine electronics.

“We have developed the product that the natural gas vehicle revolution has been demanding for heavy duty trucks,” Muller said. “Dual Flex+ is the answer to truck owners who have been waiting for a technology that can retrofit existing trucks, without sacrificing diesel engine performance.

“And the low out-of-pocket cost allows the fuel savings to payback their investment in less than a year. The distance range for trucks on our system is virtually unlimited.”

Muller did not announce the product’s price or cost of installation.

The new system will be launched around an Environmental Protection Agency approval of the system on 12.7- and 14-liter Detroit Diesel Series 60 engines up to model year 2006. D2G will soon offer additional products for Caterpillar, Cummins, Mack and International engine families up to 2006.

Muller said the company is preparing to expand its system for 2007 to 2010 engine families in the future.