I've got this vacum gauge but dont know what its for. I know it must read the vacum off the engine somewhere, but where from and why/what is it for.It's got reading from 0 to 40, then with thicker lines 40 to 76.

HELP ME

THANKS

Vacum is when the engine is pulling in air under its own power. This is cause by the movement of the pistons, with a turbo it forces air into the engine under pressure.

The more vacum you are reading the more efficient you are being on the fuel I think.

Thanks, yea the more it reads the better on fuel you are.

Vacuum on the inlet manifold on an N/A car, shopuld be more vacuum at idle/overun. Close to 0 at full throttle.

ie at idle the engine is sucking against a closed throttle plate, so vacuum.

at full throttle it should be as close as possible to 0 so the engine is doing less work trying to suck air in so (more air less losses) more power.

thats presuming it's a car gauge, otherwise you've just got a compound gauge with which you can measure other things such as the efficiency of your hoover should you feel the need

[Edited by RB5_245 - 11/30/2003 12:42:25 AM]