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Gauging usefulness
AdamR - 6/9/07 at 12:23 PM

I have the option to buy some cheap gauges and I'd like some opinions on the practical usefulness of the following:

Vacuum gauge - measures vacuum in the inlet manifold, but what does this tell you? (Apart from that if there's no vacuum you have an air leak, obviously).

Fuel Pressure gauge - might be useful whilst I'm tinkering with my EFI system, but presumably when everything is running normally, fuel pressure remains constant?

Voltmeter - tells you that state of the battery & alternator, but again not very interesting if everything is working as it should be?

Cheers.

PhilCross66 - 6/9/07 at 12:29 PM

I think vacuum gauges are used to help you drive more ecconomically, so no use at all then
Phil

BenB - 6/9/07 at 12:48 PM

Yup. Vacuum gauge ain't much use.
A remote fuel pressure gauge is only of use if you've got some fuelling problems or misfire so you can monitor the problem whilst driving.
A voltmeter is quite handy

02GF74 - 6/9/07 at 01:57 PM

agreed with what ^^^ say, unless you have a GT40 that is

even voltmeter is unnecessary - the charge warning lamp is sufficient.

scottc - 6/9/07 at 02:07 PM

Vacuum guage will allow you to 'measure' the load on the engine. as above completely pointless. Unless... you've got vacuum operated wipers

DarrenW - 6/9/07 at 03:28 PM

Didnt some old cars use vacuum gauge as an indication of mpg? or at least economy.

Voltmeter handy but not that essential.

Not sure about fuel pressure. My digi dash can display it if needed so there must be some applications somewhere that need it.

CaptainJosh - 6/9/07 at 04:16 PM

Get them all- when/if your car brakes down you will be so happy you had them

Was it a fuel starvation? was it the battery?

Just a thought

-Josh

martyn_16v - 6/9/07 at 05:59 PM

quote:
Originally posted by DarrenW
Didnt some old cars use vacuum gauge as an indication of mpg? or at least economy.


Yup, VW used to put them in Scirocco's as an economy gauge, and I think i've seen one in an old bmw....

The more gauges you have the more paranoid you become, the slightest deviation from 'normal' starts you off. I'd possibly have the voltmeter, wouldn't worry about the others.

grusks2 - 6/9/07 at 08:53 PM

I dont have time to look at the gauges my eyes are glued to the shift light and oil pressure lights

[Edited on 6/9/07 by grusks2]

AdamR - 6/9/07 at 09:50 PM

A few people have said they'd have a voltmeter, but what for specifically? What's interesting about the state of a battery? Any needle that doesn't move around until something is broken is a waste of space as far as I'm concerned.

At least the vacuum gauge tells you something about your engine... albeit something that you should be able to glean from the noise and the position of your right foot!

[Edited on 6/9/07 by AdamR]

RazMan - 9/9/07 at 08:42 PM

Actually, I wouldn't be without my voltmeter. It 'told' me that I had a loose engine earth so the alternator wasn't giving full charge to the battery - a little warning light blinked when the level went below 11.8V ....... which was nice

rusty nuts - 10/9/07 at 05:19 PM

Volt meter would show if the alternator wasn't charging as soon as you had a problem unlike the charge warning light , guess how I know! Vacuum gauge can be a useful tuning tool if you know what to look for.