A Plug-in Hybrid Vehicle (IMAGE) University of California - Riverside Caption Researchers at the University of California, Riverside have shown how to improve the efficiency of current PHEVs. Credit University of California, Riverside Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.