[s-cars] Question about Boost Gauge readings

[RubEric at aol.com]

I have an aircraft digital boost gauge in my S6. (Perfect vacuum = 0 inches  
of mercury. With engine stopped it  reads local barometric pressure .
 
I get 14.4 inches of mercury at idle, 29.9 in with engine stopped (today),  
and max of about 62 in. 
 
Eric