+vacuum meter
A vacuum gauge is to measure the pressure in a vacuum so it's usually presented in (-). A low vacuum reading indicates a leak of vacuum.
+water temp
This gauge is used to monitor your coolant temperature. Also to tell you when your engine reach operating temperature. When a water temp is low all the time, this means that your thermostat might be opening too early (except for those who change them to low temp thermostat) or the water temp sensor is faulty. If temp too high. Thermostat might have stop working, lack coolant or tell you it's time to change to KOYO 3 core radiator.
+oil temp
This is to monitor your oil temperature and tell you when your engine oil is overheating. If oil temp is very high suggest installing an oil cooler to keep oil temp in check.
+oil pressure
This is to monitor the oil pump working condition. If the oil pressure drops too much. This means that oil pump is not working at it should be or there's no oil. If pressure too high it means there's a clog in the oiling system.
+Fuel pressure
see here:
http://www.geocities.com/jonnyguru/vw/fpressure.html
+ Air fuel ratio gauge
The function of this meter is to let you know the AF ratio of the car. Similar to EGT gauge.
+Exhaust temp or EGT gauge
Is used to monitor the exhaust gas temperature of a combustion engine in conjunction with a thermocouple type pyrometer. by monitoring EGT, the driver can get an idea of the cars air to fuel ratio. Low temp = rich mixture, high temp = lean mixture.
+Boost meter
Is used to indicates manifold air pressure of turbo or supercharger boost pressure in an engine. It's also used to ensure excessive pressure is not being generated when boost pressure is being increase to levels higher than OEM standard on a production turbocharged car.
