Many gauges are available on the aftermarket, and peering into other people’s Tacomas set up with aftermarket gauges can tell you what you will need. But if you don’t understand what gauges are used for what purpose, you may end up with something you don’t need. Understanding what exactly a gauge is used for is the key to using them to pinpoint any issues.
Oil Pressure: Oil pressure in an engine is critical to its survival. Oil levels and proper tolerances in the engine are what produce oil pressure. If an engine’s oil runs low, the oil passages become contaminated, or a bearing is spun the oil pressure will drop. It’s a surprise that car manufacturers don’t equip all vehicles with oil gauges because of how important they are.
Water Temp: Toyota Tacoma trucks arrive factory equipped with water temperature gauges. However, the factory water temperature gauge doesn’t tell you exactly what the water temperature is.
Aftermarket water temp gauges will give you a numerical reading of the water temperature. This can be useful during troubleshooting as it will tell you exactly how hot the engine may or may not be and whether or not the thermostat is doing its job correctly.
Volts: The telltale signs of a failing alternator are flickering light and a dying battery. A voltmeter taps into the electrical system to tell you how much voltage the alternator is putting out as the vehicle is running.
With aftermarket additions such as lighting, winches, and sound systems this will tell you if the alternator can keep up with the job or if it is too weak.
Trans Temp: Automatic transmissions need to run at a proper operating temperature and can even overheat. A transmission temperature gauge will tell you whether or not the transmission cooler is working or if there is an issue present.
Manual transmissions are subjected to this same weakness, though many manual Tacoma owners can do without this gauge.
Boost: A boost gauge is used to tell how the PSI reading of a supercharger or turbocharger. Without forced induction these gauges are useless. If the engine in your Tacoma is factory equipped with a supercharger or forced induction is added later on this gauge can be useful for dialing in and troubleshooting the supercharger or turbocharger.
Programmable Speedometer: Programmable speedometers are incredibly useful for Tacoma owners, who intend on, or have, changed ring and pinion gears and tire sizes. These speedometers can be calibrated to match the pulse given off by the vehicles speed sensor.
