All vehicles have a dashboard installed, so why would someone want an aftermarket gauge?
Cars from previous generations did not have gauges on them for crucial data like oil pressure , coolant temperature , air fuel ratio. They had emergency lights and unfortunately some still do. When the lights went on that meant that something is wrong and at that point it was probably already late.
With gauges installed you can monitor at any point vital measurement of your car and have control on what is happening at any time and might catch a problem on it's beginning.
Especially when you are a car performance enthusiast and you have installed a turbo for your engine and made some modifications on it you want to accompany those with a more accurate monitoring.
Last but definitely not least , you just want something more elegant and cooler than your factory dashboard , aftermarket gauges is the way to go.
What types of gauges are out there?
Depending on what you want to measure there are different types of gauges. Two basic categories. Digital and analog gauges. That depends on your preferred look. Digital gauges display in numbers on their screen the measurement. Analog gauges have needles . In the digital world there are some advantages. Sensors implement new technologies , become more accurate , energy efficient and can more likely connect with third party digital gauges.
As for the measurements you can monitor.
Wideband / AFR (Air fuel ratio)
AIT (Air intake Temperature)
EGT (Exhaust Gass Temperature)
How to install.
All products come with their own instructions. Most of them need a 12V power supply. The place that the gauge will be mounted depends on the car and your preferences. You could use a mount or install it on your dashboard or anywhere else you can fit the gauge. In general the installation process is simple.