A pressure measuring device/system that is capable of measuring the pressures of multiple systems in an automobile, including fuel pressure, power steering, engine oil pressure, transmission oil pressure, compression, diesel compression, high pressure oil systems, and diesel fuel pressure, and is capable of displaying and/or recording the measured pressure values. An onboard digital display receives a series of signals from a transducer and displays the series of signals as at least one of a digital needle gauge and a live graph display, and selectively displays the series of signals in a chart with two axes, one for signal and one for time.