Gauges are an important accessory when upgrading the performance on any vehicle, alterting you if any parameters exceed safe levels. This is particularly necessary when using aftermarket performance modules which operate outside of OEM specifications.

On diesels, common gauges are Exhaust Gas Temperature (EGT) and boost gauges. On a petrol, boost gauges are popular for vehicles with forced induction, as are air/fuel ration gauges, and oil and coolant temperature gauges.