Isuzu trucks come with an oil pressure meter and battery voltage meter in the dash.. Are these actually useful instruments?? The oil pressure meter goes in kPa and for my car it reads rather low. (A bit under 6 on a scale that goes up to 15.)

Worthless in my opinion. If you run your engine low on oil, which is doubtful unless you punctured your oil pan, you will never see a fluctuation in oil pressure. Even if you run the engine low on oil, you most likely would never see the needle momentarily drop while driving through a tight corner. You'll hear the engine change tone before you notice the oil pressure gauge. Now the voltmeter is another matter. It'll be your first clue that the battery or the alternator is not functioning properly. Anything below 13 VDC or higher than 14.5 VDC is suspect when the engine is running at higher than idle speed. Mind you, your gauge probably has never been calibrated so it will have a + or - of about 5%. Note what the voltmeter reads under various circumstances now, while your truck is new, and then check it later in life to see if there's any major changes. A low voltage reading could represent an alternator malfunction. A low voltage reading while the engine is off and the ignition is on could mean the battery isn't taking a recharge like it should.

This depends on what type of gauge electric or mechanical.

A electric oil pressure gauge uses a pressure switch that activates at a certain pressure fluctuation and sends a signal to the gauge much the same as an Idiot light. Now a mechanical gauge which reads the Actual oil pressure is the only way to go. Oil pressure is very important and can help you to tell what's going on in you engine.

Most cars with an electric oil pressure gauge will also have a light. An electric gauge will tend to fluctuate before the light comes on so it might bring a problem to your attention sooner.

In our race car, all our gauges are mounted in front of the co driver along with two large indictor lights (oil& alt) and his job is to drive the gauges. If a light comes on he can check the gauge to see what is happening and make a decision weather to stop the car or not.

In my opinion gauges are very improtant, But, I'm a motorhead....

Thanks!!

In my opinion the oilmeter should be std in all cars. With a scale that normal folks could understand. In colors like red ,orange and green. Green being ok. But as the oilpump being a mechanical part it's not likely to go bad but the oil is. If the oil is full of petrol the preasure will drop indicating that the oil is poor.................... this could happen if the choke is defect or the pistonsealing is bad.

But ofcourse this is more on the sience side than everyday driving back and fourth to work.