Fiesta Fuel Gauge Fun! - Blue {P}
Just wondering if any Backroomers could come up with some ideas for what is happening to my baby.

Normally I get around 260 up to 300 miles from a tank depending on what type of driving I'm doing.

The other day I noticed that the fuel gauge seemed to have dropped dramatically, despite me only having done 140 miles, it was already under half full.

I know that you can't work out miles per gallon etc. from the gauge, and that they're not terribly accurate, but this really did seemed to have dropped by an enormous amount compared to where it would normally be at that sort of mileage. So I went to the petrol station, filled up (until the pump stopped), so I sat down, worked out my mileage over the gallons used and I had acheived 33 mpg, just 2mpg less than normal (ok I may have been driving enthusiastically!).

So somehow, despite me actually getting largely the same economy as normal, worked out according to the tried and trusted method, my fuel gauge showed a much thirstier story. As I drove away, I noticed that the last bar on the fuel gauge that indicates a full tank was not lit up, after about 5 miles of driving (one journey) I looked again and now the gauge showed a full tank. It normally shows the full tank readout read out instantly.

After more driving, I've notivced that again, the gauge is dropping quicker than it should be.

Car is a 2003 Fiesta 1.4 Petrol.

Sorry about the rambling long post, but I wanted people to know the full circumstances and everything that I have done to try and work it out myself!

Anyone got any ideas?


Fiesta Fuel Gauge Fun! - Kingpin
Sounds electronic to me. I did not realise the latest Fiesta has a sort of 'illuminated bar' fuel gauge. Perhaps it is not as accurate as a traditional needle type? Only sure way to work it out is brimming the tank and taking mileage readings etc.
You may come to realise over time that it is a characteristic of this type of gauge.
Fiesta Fuel Gauge Fun! - Blue {P}
I've tried that, the thing is, the gauge used to work perfectly, and I always take my mileage readings by brimming the tank.

It just seems to be dropping much quicker than it used to.

Fiesta Fuel Gauge Fun! - Blue {P}

Fiesta Fuel Gauge Fun! - Andrew-T
Doesn't sound electronic to me! I don't know how your car measures the depth of fuel in the tank, but I have experienced two types of gauge, and there are probably lots more than that.

Way back, some cars used a pivoted arm in the tank with a float on the end. A rheostat gave a varying reading for the dial.

More recently, Pug 205 tank has a vertical cylinder with a float inside, which is a fairly tight fit. Bits of grit accumulate in the tank and cause the float to stick - wife drove until warning light came on, but sadly it never did. Unit is easily removed from tank and rinsed out - problem solved.
Fiesta Fuel Gauge Fun! - Vagelis
It's a mental thing. You thought that the needle was going down quicker than usual, when actually everything was, more or less, normal. You have your calculated mileage to support this.

It often happens to me too: "What?! You used it up already, you french !@#$%^", and then: "UPS! Everything normal... sorry mate :-]"

As for the gauge moving around when filling up, it has to do with air being trapped in the feed hose, which then gets released, the fuel goes down to the tank and the gauge reads 'full'.

Fiesta Fuel Gauge Fun! - Altea Ego
Agree - its because you are looking at it now. But to test the gauge try this.

Top it up to full. Run it around till it shows half full. Top it up to see how much you put in (ie half a tank). Run it to nearly empty and see if you fit nearly a full tank in at fill up time.
That way you have tested full, half full, and empty for aprox gauge accuracy.
Fiesta Fuel Gauge Fun! - Baskerville
33mpg? Can that be right with a modern supermini? That is truly shocking economy for a car that size IMO. Our old Metro used to average 40mpg--and believe me you had to drive that thing hard all the time just to get anywhere. It seems Fords continue to live up to their reputation of old, or you have something wrong.
Fiesta Fuel Gauge Fun! - Blue {P}
Lol - yeah 33 mpg is hardly world beating economy, it normally acheives 35 mpg.

Bearing in mind that for a supermini it is quite heavy and it has a 1.4 engine in that I thrash the living daylights out of, after all, Ford didn't put a red line on the rev counter, which to my mind means that I can rev it as hard as I like! :-)

This coupled with A/C etc means that I'm not too surprised at the economy. It's good preperation for when I get my 318i Cabrio in a couple of years, that *will* be thirsty!

Fiesta Fuel Gauge Fun! - Baskerville
You know, Blue, if you go to Clark's I'm sure they'll be able to fit you up with a pair of boots that don't have lead weights in them ;-) I don't want to worry you or anything but I reckon looking at the fuel gauge is a sign of ageing. Pretty soon you'll be filling it up with a third of a tank left "just in case", you mark my words.
Fiesta Fuel Gauge Fun! - Vagelis
"[...] it has a 1.4 engine in that I thrash the living daylights out of, after all, Ford didn't put a red line on the rev counter, which to my mind means that I can rev it as hard as I like! :-)"

Very well put, Blue Oval. The same applies to my clio: no red line or region on the rev counter. I take it as a challenge: "Aha, so you don't have a red line, hah?"

And so I "thrash the living daylights[1]" out of it too!!


[1]: LOL! I like this little phrase so much, I think I'm going to have it in my mind for a day or two :-D
Fiesta Fuel Gauge Fun! - pastyman
It could be just a simple fault with the float arm, but, why are you asking such questions when the car is a 2003 model, it should be a case of, "Oi, mr Ford dealer, sort it.".


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