The lie of the German “truck engine” gas chambers is undone by the fact everybody knows German vehicles during the War were almost entirely diesel, not petrol. And diesel fumes are far less efficient as a gassing agent, despite being worse smelling than their gasoline counterparts. We know this because it’s always cited when discussing Hitler’s winter campaign against Stalin wherein vehicles stalled and wouldn’t drive due to the fuel turning to jelly in the Russian cold. Not so, Soviet trucks, which ran on regular leaded gas and whose fumes were perfectly suited to kill.