It is claimed that the exhaust from diesel engines was used to kill millions of prisoners in the concentration camps during WWII. The reports are always very specific about the fact that they were diesel engines - not gasoline. Even more specifically, it is stated that these engines were taken from captured Russian tanks. No Russian tank used gasoline.
The problem, as one can see from these videos, is that diesel engines produce little or no carbon monoxide. It is almost impossible (and definitely impractical) to use diesel exhaust to kill people. It is mind-boggling to think that human beings were actually sentenced to death, based on this story.