Karl Denninger wrote:

(It will pull a near-zero-zero vacuum..... as will the fuel pump, in fact.
I've seen the fuel restriction gauge showing effectively a zero vacuum when
I foolishly started the engine without remembering to turn on the fuel
valves first....)

Cringe ... zero vacuum is one atmosphere, one Bar, or around 14.7 pounds
per square inch absolute, it is no vacuum at all.

The most complete vacuum you can produce will still only create a
pressure differential of 14.7 pounds per square inch at sea level, or
one atmoshphere.

Rick