Fuel Guage

[TurkS4]

Gents,

Is there a way to change the way the fuel guage shows the amount of fuel remaining in the tank.

One of my pet hates of Audis is that the fuel guage moves on the basis of how the car is driven rather than showing you what is actually in the tank. I am amazed as to how far the needle can move either way in a short period of time.

Same thing with the A4 Quattro I still own (any Buyers?), but different on me old Audi 80, whereby this showed actual fuel in tank irrespective of how you are driving the car.

Or is this just the price we pay for a modern life [img]images/graemlins/mad.gif[/img]

cheers

[toasty]

There are ways around everything [img]images/graemlins/grin.gif[/img]

The issue with most fuel senders is that they have a linear response to the vertical movement of the float.
By this I mean say they have a travel of 10 cm and they give an output voltage between 0 - 10v then at 3cm it will report 3 volts, at 7cm it will report 7 volts etc...
The fuel guage is just a voltmeter and indicates this accordingly.

However as the tank doesn't have perfectly vertical sides and a flat bottom .... have you ever seen the S4 fuel tank [img]images/graemlins/tongue.gif[/img] then this means that should the tank narrow at any point then this will result in the fuel guage dropping rapidly at this point and the converse is tru if the tank widens.

Since the sender is just a voltage source and the guage is just a voltmeter there's no reason (IMHO) why you couldn't insert a nice box of tricks in between the two which performed some kind of translation based on the profile of the tank at a predetermined number of intervals between empty and full.

I'll give an example:
Say the tank was like an upside down triangle. This would mean that the more empty the tank got the fast the needle would fall (since the same amount of fuel would represent a greater vertical drop in fuel level.)
The box of tricks would have to compensate for this accordingly (Full would still be full and the same for empty, but half way down wouldn't mean half empty it would actually mean only 1/8 remaining)

...or you could fit a cuboidal tank. [img]images/graemlins/boots.gif[/img]

[TurkS4]

Toasty,

Thanks for the response....
Haven't got a clue what it means though (i'm technically challenged) [img]images/graemlins/confused.gif[/img], but it appears you are suggesting that a device goes directly into the fuel tank?, or are the electronic gadgets situated outside of the tank?....I was hoping this would be a job for the Vag tool.

Do you know of anyone who has changed the way the Fuel Guage reads..

Cheers

[Dippy]

Since the sender is just a voltage source and the guage is just a voltmeter there's no reason (IMHO) why you couldn't insert a nice box of tricks in between the two which performed some kind of translation based on the profile of the tank at a predetermined number of intervals between empty and full.

There already is one. It's called the Instrument Cluster combination processor. Thus there is no reason why Audi couldn't have done the signal transformation...