I have a 01 bullitt and the man who owned it before me installed a oil pressure gauge and a vacuum gauge after the car is warm and at an Idle what am I suppost to read?

It goes up to 30. What is a normal reading?

Thanks guys!

 

If the vacuum gauge is the one that goes to the 30, its in inches of mercury or InHg. Atmospheric pressure is I believe about 20 - 25 InHg depending on how high above sea level you are, so if you have a naturally aspirated 'stang you'll probably be running about 21 InHg at idle and 23 InHg on a deceleration. I hope this helps

 

Holy crap man!!! You are dead on!! I wasn't gonna say what it was yet...it's 21!!! Good job man!! I'm in Texas. So 21 is normal?

 

Here is how to interpret vacuum gauge readings:

 

That chart is great man, thanks! But yeah to answer your question a steady 21 at idle is just fine.