US Patent 7945376 Engine and method of maintaining engine exhaust temperature

In a method of maintaining temperature of engine exhaust gas from cylinders of a multi-cylinder engine (23) with a desired range, exhaust gas from a first group of cylinders (25) including at least one cylinder is routed to at least one of an EGR system (53) and an exhaust system (41). Exhaust gas from a second group of cylinders (27) including at least one of the cylinders is routed to the exhaust system (41). Routing of the exhaust gas from the first group of cylinders between the EGR system and the exhaust system is controlled to maintain a temperature of engine exhaust gas within a desired range. An engine (23), a control system (69), and a controller (71), as well as an exhaust gas mixture, are also disclosed.