controlling exhaust gas emissions within US and European standards. The telematics data is used (via Fleet Telematics Systems) by Fleet Management Systems to let fleet operators keep track of vehicle and driver performance, such as fuel consumption, safety events, and repair time. Because of the demanding standards, engine development is expensive, and truck-based engines are reused in many fields. Consequently, SAE J1939 can now be found in a range of diesel-powered applications: vehicles (on- and off-road and rail), marine propulsion, power generation and industrial pumping. See also Fleet Management System CANopen CAN FD Flexible Data Rate Open SAE J1939 References External links SAE J1939 Standards Collection SAE J1939 Top Level Document J1939 Introduction (Kvaser) Introduction to J1939 (Vector Informatik) A Comprehensible Guide to J1939 (Book) Computer buses Automotive standards Automotive software