Vacuum gauge inside of your car?

A vacuum gauge is a handy tool for some diagnostics, but I have one inside my '66 Dart to monitor how hard I'm loading the engine. I'd like to minimize fuel consumption and that gauge is the best way to do it while driving. This assumes that engine control systems are all in top operating condition and adjusted properly.

Try to keep the manifold vacuum higher than 10 inches Hg for best fuel economy.

Jerry