On May 14, 2008, the U.S. Environmental Protection Agency (EPA) issued a Certificate of Conformity to Flex Fuel U.S., LLC, for the conversion of specific 2006 model year Chrysler and Dodge vehicles to operate on E85. The certificate allows the conversion of up to 100 vehicles that are part of the model year 2006 Chrysler test group #6CRXV05.7VE0.

Models included in this test group are the 2006 Dodge Magnum, Magnum AWD, and Charger with certain 5.7L engines as well as the 2006 Chrysler 300/SRT-8 and the 300 AWD with the same 5.7L engine. Note that this certificate does not cover vehicles that operate in California and may not cover vehicles in other states that have adopted and placed into effect California emissions standards.