Toyota Aygo fuel warning

[Kwan]

Hi, I have just bought a Toyota Aygo Platinum 2008.. Im not sure if the fuel gauge is accurate

I have 2 bars of fuel from last drive, and today (no driving in between) I saw the last bar has already flashing....which I have driven 55miles to lost 1 bar. Does any one know if the last bar alway flash? and is it normal to drive 55miles to lost 1 bar?  the manual handbook said I can drive 477 miles for a full tank...the petrol seems loss quicker than it should be. I have been always driving around the city with 20-30mile limits. 

Can anyone tell if anything wrong? Many thanks:)

[forkingabout]

Many years ago when the Aygo came out, I had an Aygo in disguise 107 loan vehicle from the Peugeot dealer for a week, I started a journey with 3 bars illuminated on the fuel gauge, less then 7 miles later it coasted to a stop on a dual carriageway, I had to use the starter motor, 2nd gear & smart use of the clutch pedal to get the vehicle to roll the last 200 yards on to a filling station forecourt.

FWIW a friend of mine also ran out of fuel in a different 107 loan car from his Peugeot dealer when the fuel gauge dropped on him. 

[flash22]

Never believe what MPG the manufacturer tell you, these are done in a controlled environment, the gauge is a guestimate - try not to rely on it, go and fill the tank and get a receipt, you can then work out what was left in the tank

 

iirc it has a 35L tank - 6 marks so 5.7L per bar (1.25 gallon) - UK gallon is 4.54 L

[FROSTYBALLS]

The fuel gauge on the Aygo, and some other models, operates in a non-linear way, and the bars extinguish quicker as the tank empties. On the second generation the low fuel light comes on when there are about 5.25 litres left - I presume the first generation has a similar 'reserve'.

[Billyboy81]

Don't rely on the last two bars being accurate. Regardless of the mileage you've done never leave it more than a few miles before filling up once you hit 2 bars. That's good practice, anyway.

[Rhymes with Paris]

I did not have a bar gauge until I got a mitsubishi in around 2016, took a bit of getting used to for me.

I used to enjoy the ritual in the old cars of tapping the old style petrol gauges and watching the wildly swinging needle settle down to a rough guess.

Maybe I had delusions of being a spitfire pilot in my 1970s youthful mind.

Alas,no spitfire, apart from a 1965 triumph one, more a series of terrible old bangers that was the usual transport of young men at that time.🛩️

 

 

[Kwan]

thanks for the replies... yeah.. I'm going to check the fuel consumption with a full tank next time. does any one know is the last bar always flashing? or it would stay for some miles before flashing? Thanks 🙂

[Mooly]

This was on the Auris but might help demonstrate the non linear behaviour:

 https://www.toyotaownersclub.com/forums/topic/157794-auris-133-fuel-bar-fuel-consumption-and-all-that-stuff/

 

[Guest]

10 hours ago, Billyboy81 said:

Don't rely on the last two bars being accurate.

 

12 hours ago, FROSTYBALLS said:

The fuel gauge on the Aygo, and some other models, operates in a non-linear way, and the bars extinguish quicker as the tank empties.

My experience of both Mk1 & Mk2 models is that the first bar takes about 100 miles to go out, the second about 80, the third about 60, etc.

The 'best guess' is that when only the last bar is lit (and flashing)you'll have about 40 miles left, and when it starts beeping as well as flashing then you've got 20 miles left.

The best range I've ever got from a full tank is just over 400 miles, but I'm not an economical driver!

In nearly 45 years of car ownership I've never had a car with a linear fuel gauge.

[flash22]

TBH, i don't let mine get that low half a tank is half a tank, tank shape, baffles and sender location are a big factor

[Stecha]

I always reset the trip meter every time I fill up, and have it on show, that way you get used to what range you have left

I find 350 + miles is easily achievable before having to put some in

Of course the 6 bar gauge is just whacky

[Cyker]

The worst I've owned was the Mk2 Yaris - First 2 blocks (Out of 8! ) account for over half the tank! As in a quarter-indicated is over half the tank!!

When I first got it I was quite excited that I managed to get 200 miles on what appeared to be a quarter of the tank; That boded well, as coming from the D4D, I was expecting much worse mpg for the petrol but that would put it on par with the diesel! Happy days! I thought.

I was less impressed when the next 6 blocks accounted for ~150 miles...

I don't understand why this is still a thing with their cars - How hard is it to set up a calibration curve or use a non-linear resistance strip on the sender to make the gauge more accurate and linear?!

[flash22]

It's a resistive-based sender, so it will either be logarithmic or linear, it depends on the shape of the tank to the volume and level at a given point, a gauge is just a visual interpretation of the voltage, say a full tank is 11v and 3v is empty

then you have the calibration of the sender and the gauge, In the case of a digital gauge it's in the programming of the display

[Cyker]

Yeah! It should be dead easy to calibrate it so it gives an accurate display of fuel level, even more so now that everything's digital, but over 2 decades on and we still the same problem!

To be fair the Mk4 is nowhere near as off as the Mk2 was - It's still not that accurate but about par with the Mk1 so not off enough to get me in trouble (Unlike the Mk2, which nearly left me stranded in its early days because I greatly over-estimated how much fuel it had left! I think that was the first time in my entire life I've used a motorway services for fuel!)

 

[Guest]

10 hours ago, Cyker said:

Yeah! It should be dead easy to calibrate it so it gives an accurate display of fuel level, even more so now that everything's digital, but over 2 decades on and we still the same problem!

It seems not enough owners (and magazine reviewers) complain about non-linear fuel gauges so that manufacturers don't see any need to sort out this problem.

It's really simple to correct in the instrument firmware and would have no cost per unit, but if it's not on the priority list it just won't get done.

[haelewyn]

I always trust the bars enough to also check my 'km done since last fill' tachometer. I always reset both day trip meters to 0.. having one of them left for other purposes.

I know it can always do a minimal of 600 km, even in wintery weather.

Normally, with my measured average of less than 5 ltr/100 km in mind, I would be able to get to >700 km but I never test my luck more far than 550-600 km and keep it for exceptional circumstances to go well over 600.

If you also consider the bars on top of that..  nothing will go wrong.

I noticed the view in bars / warning light on or off, is also decided by software.

For example : when I am at 600 and know I need to do around 100 km today, I fill up with 5-10 liters if I know petrol will go down in price in the next days.

But when I start the car again after filling the 5 liter, not all things react like they should. If I buy a full tank it does indicate this immediately. 

If I remember well (!!!!) the light will be out after 5 l fill, but the bars will still show as empty as a dry sock. 

If I drive around a bit, the next time I restart the car, the indication will be right. But that would not get me into trouble with an empty tank. It will only make me believe the petrol I bought was replaced by air at the gas station.. or something like that.

Rather a false negative than a false positive ..