What's a PZEV? The Subaru PZEV (Partial Zero Emission Vehicle) is the affordable, no-compromise, eco-friendly alternative. Although the Subaru PZEV runs on regular unleaded fuel, it offers significant smog-reducing environmental benefits and delivers equal performance compared to non-PZEV cars or SUVs, including hybrids, diesels and alternative fuel vehicles. A PZEV is classified as the cleanest-running gasoline-powered car on the market and was developed to meet the air quality standards of California, the most stringent in North America. A PZEV must meet the Super Ultra Low Emissions Vehicle (SULEV) tailpipe standard and have zero evaporative emissions.