Originally Posted by kurtnkegger
I got this information by googling engine vacuum at elevation...I've understood there would be a 1" drop for every 1000ft of elevation.
When testing manifold vacuum, its important to remember that if an engine idles at 22 Hg at sea level, it will idle at about 17 Hg at 5,000, 14 Hg at 8,000 and 12 Hg at 10,000 altitude. Variations from the calculated standard, of course, are the weather conditions, the engine design, and how well the engine management system adjusts spark advance and air/fuel mixture to correspond to a change in barometric pressure.
Yep. That's why it seems that 14" isn't too bad at 7,000'. I just don't want to start replacing manifold gaskets if I don't need to.