"Gas Master" Vacuum Gauge - 1970's Fuel Economy Semi-Gimmick

Today we're checking out a Gas Master vacuum gauge from Automotive Research Corp.
This would have been installed in a car, and has a primary dial to show engine vacuum in inches, and a secondary dial for instantaneous miles per gallon.
Vacuum gauges were popular in the 1970's as a fuel saving gimmick.
The gauge won't help you save fuel by itself, but it can train you to be lighter on the throttle when driving, thereby saving fuel.

00:00 Overview
01:19 Testing
02:09 Factory Gauges
02:50 Other Types
03:21 Outro