I have one of them on the turbocharged 6 cyl Continental and I would not fly without it. – If a fuel injection nozzle plugs up on a turbocharged engine a certain disaster is going to follow and the instrument is basically the only real warning one will have of a nozzle getting choked off. – It is true that plugged nozzles will result in abnormal high fuel pressure, but when its that bad its too late anyway. The totally plugged nozzle is going to shut off the cylinder and that isn’t going to hurt much. Its the partially plugged nozzle that will kill you when it leans out a cylinder and pushes the combustion event from flamefront travel into being detonation or pre-ignition at max power. That is when the JPI will save your life or engine (if you pay attention). Anyway, I would not fly anything injected and /or Turbocharged without such an instrument.