California's Zero Emission Vehicle program began this year, requiring automakers to meet higher standards for more than a quarter of their sales in the state.
While revised down from an original call for at least 10 percent of the cars sold to meet zero emission standards - which would require power coming from a battery or fuel cell - there are still demands affecting how suppliers of plastic fuel tanks and systems produce their components.
The original 10 percent ZEV mandate now is broken down to include 2 percent of vehicles with zero emissions - which currently would equal about 250 vehicles - with credit given toward another 2 percent of the vehicle supply coming from hybrid-powered vehicles using both gasoline and electric power.
The remaining 6 percent of the ZEV credit must come from vehicles with a ``near zero'' emissions level, credited as a Partial Zero Emission Vehicle. Each PZEV car is counted as 0.2 percent of a full ZEV, which would mean that automakers must produce an estimated 30 percent of their vehicles with a PZEV credit.
To meet PZEV's emissions from the fuel system, plastic tank makers have been working to integrate systems and reduce the potential for gases to escape from joints and seals.
The PZEV fuel system must meet emissions testing guidelines for 150,000 miles or 15 years.
The state is to review the program during 2006 and 2007, and may make adjustments.