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.
For regular gasoline vehicle oxygen sensors are used to calculate the best fuel to air ratio possible. It gives fuel economy, responsiveness, power and much less pollution. But newer diesel vehicles also have that sensor. This is used to calculate precisely how much exhaust recirculation (EGR) engine needs at low power so there's minimum amount of NOx/ emission (result of too much fresh air in cylinders) and it also lowers temperatures in cylinders for better economy. Written Sep 7, 2015.