Water/Meth Injection
I've been thinking throughout the day (quiet one for flying) and was wonder if the benefits of having a water/meth injection system on an engine was of any real benefit given complications with the system and extra weight + having to have one more substance to refuel with???
I could take a guess that as they are no longer installed (on new aircraft) that they were perhaps one of those things that was "a good idea at the time".