Driving with a vacuum gauge

[Meph]

Ive been looking into pick up a boost gauge to try and max out my MPG. Ive read about the basics behind using one for economy but I'm still a little lost.

Keep in mind the car is OBD 0 so scanguage isn't an option as far as i know.

so, once this thing is installed, how do I interpret it to get the best economy?

[Ford Man]

Try to keep the engine vacuum as high as possible.

[Johnny Mullet]

Here are what normal vacuum readings should be on a properly working gauge and a properly running engine.............

IDLE - 18-22
DECEL - 22-30
ECONOMY - 10-18
POWER - 0-10

The goal to saving fuel is to monitor it while at cruising speed. Keeping a constant reading like 10-12 will net the best results. Never accel hard so it drops below 5 because that is just a waste of fuel. Watching it at idle will tell you if the engine is running properly. The gauge should really not fluctuate at idle if it's running right.

I do use mine during accel. I keep it at 10 or higher and shift whenever I feel it will not draw more then 10 for the next gear. It's usually right before the shift light comes on, but if I am going up a hill, I will stay in the gear that gives me around 10 even if this involves higher RPM's

[SVOboy]

As long as you have electronic fuel injection you could use the MPGuino.

[Meph]

can you use the gauge to find your cars peak MPG speed somehow?

[Johnny Mullet]

The gauge is mostly used for maintaining throttle position since it is very load sensitive.

[Meph]

so for best results, it would be a good idea to:

-get the most vacuum possible while cursing at a speed (something around 10-14)
-Try to maintain a vacuum close to that number when accelerating. ( i thought the general rule was high throttle and low rpm, or will that condition be produced?

Without a scangauge or MPGuino is it possible to determine what Speed/Vacuum is most efficiency?

Thanks for the help

[jim-frank]

Originally Posted by Meph

so for best results, it would be a good idea to:

-get the most vacuum possible while cursing at a speed (something around 10-14)
-Try to maintain a vacuum close to that number when accelerating. ( i thought the general rule was high throttle and low rpm, or will that condition be produced?

Without a scangauge or MPGuino is it possible to determine what Speed/Vacuum is most efficiency?

Thanks for the help

The fuel usage is directly proportional to the throttle opening, the RPM, and inversely proportional to the vacuum. Try to maximize vacuum while minimizing throttle opening and RPM's, and you'll be on the right track. The efficiency of the engine won't be reflected in these factors, if I understand right, so you won't be able to see peak efficiency with enough accuracy to really be helpful.

[Meph]

got the gauge installed today, I'll see how it works out tonight.

Thanks guys

[fud2468]

Sure it's fuel-injected?
He says it's OBD-0 so maybe he means it's a carbed car.
Ray Mac