While driving that long straight road from WY to SD (16) on our way to Custer, I had a chance to monitor my dash air gauges for longer than just a quick glance every once in awhile.<br/> Here is what I noticed. At 60 MPH both the fwd and rear dash gauges would cycle from about 100 to 125 PSI constantly. A few seconds to 125, then a few seconds to 100. I can't ever recall...