How do i read the oil pressure gage in the car?

when the car is in idel position it reads 1 1/2 in drive it goes to 3 and i just changed oil too does it mean i need more oil or what?How do i read the oil pressure gage in the car?
You check how much oil you have ';only'; by the dip stick.





If there is enough oil for your oil pump to pump then your oil pressure gage will measure it as 0. Good pressure is around 30 to 60 psi. At idel it can drop down to 7psi. You have to read the gage if 1, 2 or 3 means anything such as ';X10PSI.';





There is a ';pressure control valve'; besides the oil pump that determines oil pressure.How do i read the oil pressure gage in the car?
refer to your owner's manual.
A oil pressure gauge is read in pounds per square inch ( psi )


just be sure that you have enough oil in the engine by reading the level on the dip stick, DO NOT OVERFILL. If you are in doubt about the pressure, take it to a reputable mechanic and have it checked to be sure all possible problems, if any, are looked at.
Proper procedure is as follows:





%26gt; Run the car engine until it gets warm


%26gt; Turn it off %26amp; wait about 10 or 15 minutes


%26gt; Pull the dip stick out of the oil reserve


%26gt; Wipe off all the oil with a clean, dry rag


%26gt; Insert the dip stick back in to the oil reserve


%26gt; Pull it out again %26amp; read the results





Repeat the last 3 steps to verify results
The oil pressure gauge is meant to be an indicator only.





Different gauges work a little differently. They are usually pretty standard for all the cars of a particular brand. Ford gauges tend to become defective more often then other brands I have seen. When they do they read too low which is a good thing because it gets your attention.





Oil pressure builds up gradually as the engine rpm increases. Usually an indication of over 1/2 of the guage travel is normal for highway. The important thing about an oil gauge is that you know what it normally does so that you can tell when it is not reading normal.





When the engine is idling the pressure will gradually decrease to a lower level then it has for highway speed. Quite frequently this will mean that it will read below the 1/2 mark. This is nothing to be alarmed about.





You should be alarmed if it is not reading normal for the current speed of the engine.





When you are really low on oil, The pressure cannot builld up properly. This is definately something to be alarmed about. Then it is time to shut off the engine before you burn it up.





As an engine ages the oil pressure will decrease very very gradually.