Gauges

Tachometers:

A tachometer (also called a revolution-counter, rev-counter, or RPM gauge) is an instrument that measures the rotation speed of a shaft or disk, as in a motor or other machine. The device usually displays the revolutions per minute (RPM) on a calibrated analog dial, but digital displays are increasingly common. The term comes from  tachos, "speed", and metron, "to measure".

 On analog tachometers speeds above maximum safe operating speed are typically indicated by an area of the gauge marked in red, giving rise to the expression of "redlining" an engine revving the engine up to the maximum safe limit. The red zone is superfluous on most modern cars, since their engines typically have a rev limiter which electronically limits engine speed to prevent damage. Diesel trucks with traditional mechanical injector systems have an integral governor which prevents over-speeding the engine, so the tachometers in vehicles and machinery fitted with such engines sometimes lack a redline.

The Air to Fuel Gauge:

An air-fuel ratio meter monitors the air-fuel ratio of an internal combustion engine.  Also called air-fuel ratio gauge, air-fuel meter, or air-fuel gauge. It reads the voltage output of an oxygen sensor sometimes also called lambda sensor, whether it be from a narrow band or wide band oxygen sensor.

The original narrow band oxygen sensors became factory installed standard in the late 70's and early 80's. In recent years, a newer and much more accurate 'wide band' sensor, though more expensive, has become available.

The Boost Gauge:

A boost gauge is used to ensure excessive pressure is not being generated when boost pressure is being modified to levels higher than OEM standard on a production turbocharged car. Simple methods can be employed to increase factory boost levels, such as bleeding air off the wastegate diaphragm to 'fool' it into staying closed longer, or installing a boost controller.  To prevent the Air-fuel ratio  from going lean (caused by increasing the boost beyond the fuel systems capacity) care must be taken to monitor boost pressure levels, along with oxygen levels in the exhaust gas, using an Air-fuel ratio meter that monitors the oxygen sensor.

 A few of the most common Gauges are for the following:

• Oil Pressure
• Oil Temperature
• Fuel Level
• Water Temp
• Voltmeter
• Vacuum
• Tachometer       

There are many  manufacturers of various styles and types such as just to name a few

• AutoMeter
• Greddy
• AC-Autotechnic
• AEM

Guages