Traditional multi-cylinder exhaust gas and cylinder head temperature systems that force the pilot to switch or scan an indicator from cylinder to cylinder in search of critical engine data, are long obsolete. Using the latest computer technology, the G4 presents a clear, concise, graphic picture of all engine temperatures simultaneously for interpretation at a glance.

Never before has so much engine diagnostic information been available to the pilot and never before, has the pilot been able to control mixture with such ease and precision for peak fuel efficiency.

Insight's latest G4 automatically records flight temperature and will also interface with other data sources and report information to other instruments like MFD’s. The data-log files stored on the SD card can be easily retrieved by the pilot, in-flight or post-flight, for instant viewing or permanent record-keeping.

The G4 is a sophisticated tool for engine management. Its microprocessor performs many tasks that used to be handled by the pilot. One of the basic functions performed by the G4 is monitoring exhaust gas temperatures for all cylinders with one degree resolution. What is important is the exhaust gas temperature of a particular cylinder in relation to its peak. But peak EGT is not a constant; it changes with atmospheric conditions, altitude, power setting and engine condition and for this reason absolute exhaust gas temperatures in degrees Fahrenheit are quite meaningless.

The real objective of mixture management is finding a mixture setting which represents the correct position on the EGT/Fuel Flow Curve. As we will see later, this abstract task is easily accomplished by the G3's microprocessor which samples EGT's for all cylinders many times a second and subjects this data to a complex mathematical analysis can identify peak. This capability allows the pilot to operate his or her aircraft engine at the most economical mixture settings.

It is generally known that EGT can be a valuable source of information for engine diagnosis and troubleshooting, but there is a great deal of confusion when it comes to interpreting this data. One of the basic principles of EGT engine analysis is that engine temperatures (EGT and CHT) achieve equilibrium in an engine operating at a constant power and mixture setting. What is often overlooked is that this equilibrium cannot be defined as a single point but rather a range of temperatures.

The Graphic Engine Monitor is ready to operate the moment electrical power is applied. Within seconds after starting the engine, the white EGT bar graph columns will begin to appear on the G4 display. Each column corresponds to the Exhaust Gas Temperature (EGT) of a cylinder. The lowest exhaust gas temperature that can be displayed by the G4 is 800° F. In some engines, the throttle will have to be opened to the fast idle range to get an EGT indication for all cylinders. As the cylinder heads begin to warm up, the display will indicate Cylinder Head Temperature (CHT) for all cylinders as a smaller green bar in each EGT column. A horizontal red line across each column represents the maximum allowable CHT. Digital numbers below each bar graph column indicates the exact EGT and CHT for each cylinder.