egr stands for exhaust gas recirculation on a diesel.
what does egr stand for on a diesel?
exhaust gas recirculation
the first egr systems were crude; some were as simple as an orifice jet between the exhaust and intake tracts which admitted exhaust to the intake tract whenever the engine was running. difficult starting, rough idling, and reduced performance and fuel economy resulted. by 1973, an egr valve controlled by manifold vacuum opened or closed to admit exhaust to the intake tract only under certain conditions. control systems grew more sophisticated as automakers gained experience; volkswagen’s "coolant controlled exhaust gas recirculation" system of 1973 exemplified this evolution: a coolant temperature sensor blocked vacuum to the egr valve until the engine reached normal operating temperature. this prevented driveability problems due to unnecessary exhaust induction; forms under elevated temperature conditions generally not present with a cold engine. moreover, the egr valve was controlled, in part, by vacuum drawn from the carburetor's venturi, which allowed more precise constraint of egr flow to only those engine load conditions under which is likely to form. later, backpressure transducers were added to the egr valve control to further tailor egr flow to engine load conditions. most modern engines now need exhaust gas recirculation to meet emissions standards. however, recent innovations have led to the development of engines that do not require them. the 3.6 chrysler pentastar engine is one example that does not require egr.
exhaust gas recirculation
ea288 engine family is based on ea189 engine family. ea288 diesel shares displacement, , stroke and bore ratio with the ea189 and the new ea211 gasoline engines. it is a family of 3-cylinder and 4-cylinder diesel engines featuring modular diesel engine system (mdb (modularer dieselmotorbaukasten)), with dual-loop egr system, with high pressure egr and a cooled low-pressure egr loops; variable valve train (vvt) with a camshaft adjuster, bosch crs 2-20 2000 bar common rail injection system, cylinder pressure control, a modular close-coupled aftertreatment system that includes a flow-through catalyst followed by a wall-flow diesel particulate filter (dpf). euro 6 and us tier 2 emission compliance is achieved via nox adsorber-based system for smaller size vehicles or urea-scr system for larger vehicles. other features included low-friction bearings for the camshaft and balancer shafts, piston rings that have less pre-tension, a two-stage oil pump with volumetric flow control.
list of volkswagen group diesel engines