When scavenging the local self-service junkyard for parts to put on our 24 Hours of LeMons car, I spotted this '84 Peugeot 505. Because you always see entertainingly weird stuff in French cars, I took a look inside this one... and, sure enough, there it was: the Econoscope! At first I figured it was just a clever name for the tachometer, but then I saw the three lights below the "Econoscope" lettering. I assume the Econoscope is just a vacuum sensor that indicates low vacuum or high vacuum, but it can't be so simple; this is a French car, after all!
I was tempted to pull out the Econoscope apparatus and add it to Wanky the Safety Cat, in order to enhance my driving safety.