Originally Posted by sonic656
Ive never seen a negative number on a boost gauge unless you are dealing with BAR. 15-20inHg is normal for idling in my experiences. I've never heard anyone talk about negative PSI, its always vacuum(inHg).
Sorry for double posting on C7.com I figured it would get more traffic over there then here.
My boost gauge shows -PSI when idling and driving until I hit it hard. Remember, they are putting more and more electric stuff on cars so less is driven off vacuum I think. I don't think they have to run the same kind of vaccum they did 10 years ago.