MESA provides engine and chassis tests through both a network of U.S. laboratory-based facilities, as well as Portable Emissions Measurement System (PEMS), “integrated” PEMS (iPEMS), proprietary engine cell & full chassis dynamometer capabilities – to evaluate environmental performance through measured fuel and emissions metrics. These tests can help evaluate the environmental performance of alternative and biodiesel fuels, renewable energy and emission-reducing technologies and provide independent third-party verification of vehicle and greenhouse gas emissions.