The name Minneapolis is attributed to Charles Hoag, the city's first schoolteacher, who combined mni, a Dakota Sioux word for water, and polis, the Greek word for city.
EGR valve on top of the inlet manifold of a Saab H engine in a 1987 Saab 90. In internal combustion engines, exhaust gas recirculation (EGR) is a nitrogen oxide (NOx) emissions reduction technique used in petrol/gasoline and diesel engines. EGR works by recirculating a portion of an engine's exhaust gas back to the engine cylinders.
An exhaust system is a set of metal pipes that carries away noxious emissions created by the combustion of gas usually from an automobile engine. The exhaust system must work properly for a vehicle to run reliably and safely. Modern exhaust systems typically clean up the gases before releasing them into the environment.