I took some pictures. The first one is just idling and reads around 0.1 volts and the second picture is me quickly alternating reving on and off the engine just to make the guage read higher. It's about the same reading I got while actually driving. Just reving the engine up to high RPMs didn't raise the reading (it was still down near 0.1 volts).
FYI, the guage is set to the first black scale with the numbers 0, 50, 100, 150, 200, 250 which relates to the voltages 0, 0.5, 1.0, 1.5, 2.0, 2.5 volts.
After taking these pictures I'm still very confused about what's going on with my car. It's confusing to think about.