Only 50 Miles From First 'bar' Of Fuel?

[DavidAygo]

Hi All

I just filled up on Wednesday and having got 64.3 mpg from the last tank full, (a record, my previous best has been 'only' 57 mpg) the first bar of fuel is gone at just 50 miles. Nothing has changed, just the same journey to work and as you can see I thought I was driving even more efficiently. I have not been driving harshly and as we all know usually the first bar lasts at least 100 miles.

I did notice that the reserve bar started to flash earlier than before this time, as I put nearly 29 litres in the Aygo, after driving 15 miles. Where as previously, the last bar flashes and after drving approx 30 miles, passing the faster bar flash too put in 34.7 litres on two occasions and was rather surprised at how close to the limit it was!

Is there something wrong? It's a 59 plate Platinum, I have owned for 3 months.

[Jan&tone]

Seems odd. Do you 'brim' the tank when you fill up?

Our Aygo seems to do 100/120 miles from full before it moves off the first bar, then the others go in rapidly increasing order - I understand that the Aygo's tank is v shaped so that would explain that. I never let the tank go below 2 bars though, I'd rather have petrol than maybe get stuck somewhere:)

[DavidAygo]

Seems odd. Do you 'brim' the tank when you fill up?

Our Aygo seems to do 100/120 miles from full before it moves off the first bar, then the others go in rapidly increasing order - I understand that the Aygo's tank is v shaped so that would explain that. I never let the tank go below 2 bars though, I'd rather have petrol than maybe get stuck somewhere:)

Thanks for the reply. Yes the tank was 'brimmed'. It wasn't until 4-5 'clicks' of the pump I stopped filling and was surprised at how 'little' fuel I required. If the tank wasn't quite brimmed this time, my fuel consumption figures will be messed up for last time and this. hmmmmmm.

I know the tank is V shaped and have read about the bar -especially over on the city bug forums. I don't mind getting to the last bar, and don't intend to cut it fine. Hence filling up earlier now. On previous occasions I hadn't meant to cut it fine. I just wanted to find out the amount of fuel left at the flashing and fast flashing points as I have had the car for only three months. I didn't realise it went from flashing to fast flashing so quickly!

And I too, usually get 100-115 miles for the first bar.

[Unklian]

My last tank was exactly the same.

Filled with the usual 3 "clicks" but...... at a different garage than usual.

Surprised how cheap the fill-up was. Brilliant mpg.

I was at about 60 miles when the first blob went. Nowhere near my usual figure.

After a moment's panic,

I think I must have used a pump with a very sensitive cut-off. Hence the brilliant mpg?

My Aygo has been perfectly normal since.

I think that like me, you've filled normally but the pump

wasn't behaving in the normal fashion. You're about 3-4 litres short which

would explain everything.

Ian.

[MartyB]

My old C1 use to get 130 from the first bar but the Aygo manages under 100, same journey. I filled up today and only got 325 miles from £32 at £1.18.9, thats 10p a mile, more than normal but maybe its the cold weather here? Use to get 7-8p per mile in the C1

[DavidAygo]

My last tank was exactly the same.

Filled with the usual 3 "clicks" but...... at a different garage than usual.

Surprised how cheap the fill-up was. Brilliant mpg.

I was at about 60 miles when the first blob went. Nowhere near my usual figure.

After a moment's panic,

I think I must have used a pump with a very sensitive cut-off. Hence the brilliant mpg?

My Aygo has been perfectly normal since.

I think that like me, you've filled normally but the pump

wasn't behaving in the normal fashion. You're about 3-4 litres short which

would explain everything.

Ian.

Thanks Ian, I do believe that was the case. It was at a different garage. I will have to estimate prior fuel consumption.

I have read though, that the C1 does seem to have slightly different 'reference points' for the fuel bars. I wonder if they are programmed differently.

[Jan van de Wouw]

The tank isn't as V-shaped as people seem to think...

Since you mentioned that your previous tank gave better economy I suspect the tank wasn't as full as you

thought it was. That's exactly the reason I allwas fill up the entire filler neck up to the bottom of the filler cap.

This is the only way to know for sure that you've filled it the same as before (well within about 0,05l I guess).

The mechanics in a fuelling pistol can't be trusted to work the same every time, as they depend on

temperature, angle of the pistol in the filler AND sideways, speed of the fuel through the pistol,

size of the filler neck and so on. And I'm not even takeing differences between pistols into account:

I allways fill up at the same petrol station, at the same pump, with the car withing 4" of the same

position. And even within about half an hours time window on that day (I fill up weekly, as I pass

a VERY cheap station every week and drive too much to get 2 full weeks in between fillups).

[geezbeez]

You cant read much from first bar. The bars are only accurate to a cuople of litres either way Id guess.

Its digital - so to prevent the bars from flashing on and off annoyingly at certain fuel levels -

The fuel level to make a bar disapear has to be lower than that to make it reappear (i.e not the same).

If you live some where hilly of drove up a long steep hill after 50 miles the first light will go out sooner than if you live or drive somewhere flat due to the uneven level in the tank. Same goes for all the other lights.

I have a set of traffic lights near me where I have to wait often on a slope. I stop on the slope waiting for the lights and quite often after about 5 seconds of waiting I loose a bar on the fuel guage.

Consolation if the first light went out very early you may get over 100 miles on the second light.

[grin factor]

The car will use more fuel in the cold weather too.

[DavidAygo]

Thanks for the replies.

UPDATE: I have filled it up since (at a different filling station) and I think it is back to normal. I just never thought the pump did not fill the last few litres!

However, I took the Aygo to a Toyota dealer to have a replacement door mirror, I believe this is a weak spot, since now both of mine have been replaced. I had just lost the second 'bar' of fuel but once the job was complete (half hour at most) the guage said just one bar was missing. Clearly it had been taken into a warm workshop for the duration but it wasn't until I had driven it 10-12 miles that the bar went again.

I always thought an engine was more efficient in the cold weather as, for a given volume of air, there would be more molecules, and once compressed, have a great expansion force once ignited. Now I know that there is greater friction in the cold and a greater load on the Battery from heaters/ wipers/ lights etc....perhaps that just outways it?

[AYGOgummy]

I was always told cars are more efficient when it's warm. The engine doesn't have to work as hard in warmer temperatures. My excellent Summer fuel economy reflected this, possibly proving that a car is more efficient during the Summer months.

[Mord]

I allways fill up at the same petrol station, at the same pump, with the car withing 4" of the same

position.

Seriously mate.. you need to find a girlfriend haha :D

[Jan van de Wouw]

I allways fill up at the same petrol station, at the same pump, with the car withing 4" of the same

position.

Seriously mate.. you need to find a girlfriend haha :D

I know, working on it :D