Gas van Gas van A gas van or gas wagon ( ("dushegubka"); ) was a vehicle reequipped as a mobile gas chamber. The vehicle had an air-tight compartment for the murdered victims, into which exhaust fumes were transmitted while the engine was running. The murdered victims were gassed with carbon monoxide, resulting in death by carbon monoxide poisoning and suffocation. The gas van was used by the Soviet secret police in 1930s. During World War II Nazi Germany used gas vans on a large scale as an extermination method to murder inmates of asylums, Romani people, Jews, and prisoners in occupied Poland,
Exhaust gas recirculation Clogged EGR valves can sometimes be cleaned, but replacement is necessary if the valve is faulty. In modern diesel engines, the EGR gas is cooled with a heat exchanger to allow the introduction of a greater mass of recirculated gas. Unlike spark-ignition engines, diesels are not limited by the need for a contiguous flamefront; furthermore, since diesels always operate with excess air, they benefit from EGR rates as high as 50% (at idle, when there is otherwise a large excess of air) in controlling NOx emissions. Exhaust recirculated back into the cylinder can increase engine wear as carbon particulates wash