I was reading one of the things on gas mileage, and someone said to get a vac gauge, that said like "good and bad" i looked on summit for vac gauges and all i found were boost gauges kuz im guessing they run of vac pressure, can anyone help me here? or explain to me what it is

 

Goto www.jegs.com search for 'Vacuum Gauge " You'll find tons of them.

 

During the 70s when everyone started to get worried about mileage, you could get vacuum gauges that said your mileage was "good" when vacuum was high, and "bad" when vacuum was low. It's really just a source of feedback so you can train yourself not to put your foot so far into it all the time.

I don't know if you could still get a gauge marked that way today, but it doesn't matter, a normal vacuum gauge marked in inHg does the same thing and is probably more useful if anything.

 

You can get gauges that tells vac w/o boost pressure. I have an auto meter sport comp 2-5/8" vac gauge.

If you get one that reads in inchs like the auto meter. The hand will sit to the far right on 0. With car ideling it will be somewhere between 10 and 18 based on engine, cam, etc

When driving norm., steady throttle, etc it will read in the 20's
Any time you floor the throttle it will drop to 0 then start picking back up

The idea of saving fuel with the gauge is.. Drive so you keep the highest vac reading. As long as the hand is over to the center or left your not useing as much fuel. When that hand is over to the right, your useing more fuel

OH BTW.. I think I seen one in the JCW catalog that was marked for good gas mileage and bad gas mileage www.JCW.com