Natural Gas Fueled Hybrid Truck (IMAGE) Southwest Research Institute Caption SwRI developed and demonstrated a state-of-the-art natural gas-fueled/hybrid powertrain for medium- and heavy-duty applications. The medium-duty natural gas hybrid demonstration truck reduced greenhouse gases by 25% relative to standard diesel-powered trucks. Credit Images/Videos may be used by the public for educational and informational purposes only. Usage Restrictions Southwest Research Institute License Original 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.