The US Environmental Protection Agency (EPA) has certified NaturalDrive Partners, LLC’s dedicated compressed natural gas (CNG) retrofit of 2008 Chevrolet Impala sedans powered by 3.5-liter and 3.9-liter V6 engines in models LS, LT, LTZ, as well as law enforcement packages 9C1 and 9C3.
The retrofitted CNG Impala reduces NOx and CO emissions more than 50% compared to gasoline the gasoline versions, and offers about a 15% reduction in CO2 compared to gasoline. With the 3.5L engine, fuel economy is 19 mpgge city and 30 mpgge highway. The retrofit on the LTZ model also leverages GM’s Active Fuel Management (cylinder deactivation) for superior fuel economy.
NaturalDrive’s retrofit package includes a compressed natural gas sequential digital fuel injection system and 10.4 gasoline gallon equivalent storage in Type 3 composite fuel cylinders. An additional optional cylinder provides a total of 13.0 gge storage, for a maximum highway range of more than 375 miles @ 3,600 psi. The 3.5L engine delivers 212 hp and 190 lb-ft of torque.
After conversion the CNG Impala offers 14 cu. ft. of cargo volume.
The NaturalDrive retrofit recalibrates the factory powertrain control module (PCM) to provide exceptional performance with low emissions while retaining all of the engine diagnostics and scan tool capability found in the original gasoline configuration. A new pressure regulator system design allows low pressure natural gas to flow to the engine using existing GM fuel lines while high pressure fuel is contained in the rear of the vehicle in lightweight cylinders. Since Chevrolet Impalas are already designed to run on E85, engine seats and valves are hardened for excellent long term durability while operating on 130 octane compressed natural gas.
The retrofit requires no additional wiring, no cooling to be run to the regulator and minimal tubing to be installed on the vehicle. Authorized conversions can be installed in less than 45 minutes.
NaturalDrive’s 2008 CNG Impala is available now via authorized installers in Oklahoma, Utah, Arizona, Alabama, Colorado and Indiana, with Texas and Florida opening soon. EPA certification for model year 2009 is expected to be complete by year end.
Oklahoma State University (OSU) is scheduled to purchase 10 of the Impala CNG sedans. OSU President Burns Hargis already has said the university plans to build a CNG fueling station on its Stillwater campus.
NaturalDrive is also working on the certification on the 2008-2009 Chevrolet-GMC Suburban-Yukon XL, Tahoe, Yukon, Chevrolet Avalanche and the Chevrolet-GMC 1/2 ton pickups with the flex-fuel 5.3L engines, according to co-founder Kevin Fern.