How do you read an oil pressure gauge?

[ChiGGz]

My car came with an aftermarket oil pressure gauge and I was wondering how was i supposed to read it?

On cold startups (almost winter cold) it reads 80 PSI, my guess is because the oil is really thick. Then as it warms up to operating temperature, it hovers at 20 PSI (thin oil?)

When I gas it, it goes up almost proportionally to my RPMs.
But what are the safe values and what should I expect in different scenarios.

Sorry, I tried looking for the answers but came up with a whole lot of junk threads.

Also, how do I read Gas Pressure?

Thanks for your patience!

 

[Nanan]

The normal opperating oil pressure ranges from 18 to 100 psi on DSMs. Going past either extreme is bad for your engine.

Normal values:
Cold start = 50-80 psi
Cold idle = 50-80 psi
Warm idle = 20-40 psi
3000+rpm = 40-80 psi

These readings will differ if the engine is really worn out or a new build, engines with the balance shafts removed and block off bearings installed will on avg see a 10-14 psi higher value across the board.

Thin oils will give lower psi readings, thicker will give higher. Many argue as to which is the best wt of oil to use but really it depends on the climate you live in and the avg temps.

I personally run 10 w30 Mobil 1 and have been doing so for the 4 years I have owned the car.



Fuel pressure can be read at any point previous to the fuel pressure regulator. I remember seeing a nifty writeup that someone did with drilling and tapping the banjo bolt on the fuel filter in the engine bay. Many of the aftermarket FPR have the ability to add a fuel pressure gauge.

 

[RamenPride]

oil pressure should be no lower than 11.5 psi at idle. on cold, winter days I'll get past 100psi until the car warms up (my gauge only goes up to 100psi). highway crusing it's around 70psi.