Do all types of cars give the same readings when being tested on a vacuum gauge?

Question

Import, European, Domestic, they all give the same readings, right?

Answer 1

In short, yes and no.  Heres why:

Generally the smaller the engine the less vacuum is produced since there is a lack of internal volume.  A 4 cylinder that is mechanically sound should produce between 12-15 inHg of vacuum whilst an 8 cylinder that is mechanically sound can get between 18-24inHg.  So yes, a 4 cylinder no matter who makes it can get the same vacuum reading but it all depends on the size of the engine.  Same goes for 6 and 8 cylinder engines.

Answer 2

no

Answer 3

geshtal is partly right, but there is more to it than that.  I have a car with a 468 big block chevy and there is barely (not enough) vacuum for my power brakes because of the camshaft specs.