Discover the Most Popular Car Gauges
Apart from the standard speedometer, tachometer, fuel, and temperature gauges in most car dashes, there’s not much else to tell you how the engine is performing under different loads. And this Is more evident in cars with forced induction. The industry is galloping towards turbocharged petrol and diesel engines, but carmakers have for some reason skipped the addition of gauges that monitor vital engine info relating to turbo boost pressure, air and fuel ratios, and oil pressure, or basic data that you need to avoid damaging vital engine parts when pushing the car and engine harder.
The good news though is that these gauges are widely available in the aftermarket. This is the same place to shop if you’re in any way modifying your car (for instance by changing to a new steering wheel) or bumping up performance with the addition of new engine internals, or bespoke forced induction parts like bigger intercoolers, revised intake manifolds, wastegates, and faster-spooling turbines. If you’ve already had your car kitted and modded, then aftermarket car gauges can help you get a sense of how far the engine can go, before having to deal with overly expensive repair bills.
Essential Gauges in any Turbocharged Car
Downsizing and rigorous emissions legislation has meant the demise of bigger, naturally-aspirated V8 and V6 engines, which are now steadily being replaced with turbocharged inline 4-cylinder variants. These need to crunch similar power numbers as their bigger defunct siblings, albeit with lower fuel use. The smaller engines undergo high stresses due to the increase in pressure and temperatures in a smaller displacement, while at the same time having to spin at insane revs. In poorly engineered cars, one of the first parts to go is the turbine. What follows is complete engine failure.
With this in mind, aftermarket auto gauges let you get the last strand of power and then alert you that it’s time to ease off the acceleration pedal. Equipping your car with the essential gauges is one way to squeeze out all the engine has to give and still keep it in the best condition. Here are the three gauges you want in a car with a turbo:
Boost Gauges
A boost gauge displays the amount of boost (or compressed air) a turbocharger or supercharger is making and is especially important in modified cars producing power exceeding stock figures. Keeping an eye on boost levels will let you control the performance levels of the turbo before too much boost causes premature parts failure. Aftermarket gauges are more accurate as they don’t rely on the ECU but display real-time measurements with the help of a probe placed directly in the intake manifold. This collects a specified amount of air from the throttle body and the pressure of the air is what moves the boost gauge needle. This is in mechanical gauges. Electronic variants collect pressure readings from the turbo’s air compressor and relay that info to the gauge.
Gauges can present a negative reading, or vacuum, meaning the turbo is yet to engage and push compressed air in the intake manifold. Once the turbo kicks in (at a specified rpm range), readings steadily rise alongside engine speeds. Results can be in either PSI or Bar, with moderate boost levels around 15-20 PSI (or 1.03 to 1.38 Bar) depending on the engine and vehicle. If the engine reaches excessive or over-boost, the gauge uses visual or audible alerts (or both) to inform drivers to back down on the throttle.
Oil Pressure Gauges
Oil pressure gauges monitor the amount of oil circulating in the engine. Oil lubricates moving engine parts, prevents possible friction, and serves as a secondary cooling system. This is when there is the right amount of oil and the right pressure. As with boost gauges, your car may have a factory oil pressure gauge, but these aren’t exactly the last word in accuracy.
Readings on these aftermarket gauges for car can range anywhere from 0 to 100 PSI, with normal measurements between 25 to 65 PSI, depending on engine load. A zero reading is common at idle, but at higher RPMs this can signal a drop in oil pressure, a faulty oil pump, blocked oil passageways, or a faulty gauge. Low readings (below 20 PSI) point to low oil levels, oil leaks, or worn parts. And high oil pressure readings (above 70 PSI) can mean anything from clogged oil filters, contamination or the use of the wrong oil, and advanced damage to engine parts caused by excessive friction and overheating. While oil pressure normally rises with the engine running longer and when you accelerate, it settles to a specified measurement.
Gauges measuring oil pressure can be electronic or mechanical, and both are fairly accurate. Electronic gauges are regarded as safer as they don’t need a direct link from the engine to the gauge inside the cabin. Any damage to the lines or hoses can mean hot oil spraying inside the car.
Air/Fuel Ratio Gauges
These work by interpreting the measurements picked up by the Oxygen sensor in the exhaust and sent out as a voltage. Knowing the air-to-fuel ratio will determine whether the engine is running a rich mixture, with more fuel, or a lean mixture, with more (or excessive amounts of air). Most engines hover around an optimal mixture of 14,7 parts air to 1 part fuel. But this can change due to dozens of reasons. First is boost pressure, with more air sucked in by the turbo. Another is rising temperatures in the cylinder. And when these go overboard, expect heat gaskets, pistons, conrods, and valves to start disintegrating. This is a dangerously lean mixture, first leading to detonation without ignition (due to very high pressure) and soon afterwards a wreck of metal that was once your engine.
Rich mixtures, ranging around 10.5:1 often aren’t a cause for concern, until you see black smoke from the exhaust. The best way to be informed about your engine’s air/fuel ratio is with a wideband air/fuel gauge. These are necessary for any turbocharged or supercharged car, as well as cars modified for more power.