Fuel-efficient tractor (IMAGE) Purdue University Caption Agricultural tractors and implements use a lot of hydraulic power. By creating new solutions to optimize their hydraulic control systems, Purdue researchers (left to right) Andrea Vacca, Xiaofan Guo, Patrick Stump, and Jake Lengacher are working to make tractors more powerful and fuel-efficient. Credit Purdue University photo/Jared Pike Usage Restrictions No restrictions. License Public Domain 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.