Fuel Guage

[n1ckm]

Hi everyone

I'm new here and have just puchased my first iQ (1.0).

I'm particularly interested by this thread as I filled up on Sunday and today the last bar on the fuel guage started flashing - I've done approximately 200 miles of urban stop start driving and I've no idea how much I've got left in the tank.

I appreciate that the tank is tiny, buy I would have expected to have got more out of a tank even with the type of driving that I do ??

[dash]

If you fill it to the brim now you'll discover how much is still remaining in the tank when the last bar starts flashing. You might be surprised (when you subtract what you put in from 8 gallons), just how much fuel you still have in the tank !!

Based on my experience, you're probably getting around 38 to 40mpg

Dave

[aaronfife]

I agree on the 1.0 not needing the 98RON fuels. I've tried it 3 times in a row to make sure but I actually got less MPG than standard fuels. I'm getting around 350miles until the bar starts flashing - I try to fill up asap as I'm unsure how far I'll get with the bar flashing. If Dizeee's calculations are correct that will see me around 430miles?

Usually takes £35 to fill from flashing last bar & i try hard to go easy on the gas. Occasional blast but thats only a few times on a tank!

[s44gtw]

Arron

the difference was that mine where Euro 5 engines & Multidrives and were getting driven quite hard sometimes,

but i did try on all sorts of runs.

(The ECU does seem to just re adjust after the little pleasant surprise it gets, and thinks lets just go back to running)

Also remember that in Scotland from November to March the Minimum Octane can be slightly higher than the 95 ron minimum so we can benefit.

This winter not being cold we did benefit with it IME.

(This is not to do with Winter Diesel, this is Scottish refinery petrol, in a simlar way to some European Petrol being better than others, the south stations inported stuff can sometimes be on the Minimum RON at any time)

We used in the early days of 'Super Unleaded', buy and store our Fuel from mid winter to use in the summer at sprints etc, but it does not store well so we stopped doing that years ago.

george

[aaronfife]

I understand what your saying but I didn't see any difference in MPG or performance while on V-Power. It's a 1.0 and doubt it will benefit from any +RON fuel. Even with the slight increase in Scotland over these months is so small thats it works out the same. I would be interested on how many more miles I'll get after the last bar starts flashing?

[craggle]

Just thought I'd add that I looked tonight when I got back at my average MPG reading on the trip computer.

I worked out the long winded way above that my car did 52.4 on the last tank and the trip computer said 54.1 so not far out really. :)

Craig.

[s44gtw]

Arron

part of the thing is if you set off from a cold start even at this time of the year and ambient temp and drive for 15 minutes your engine is only just up to optimum running temp, coolant is quick but oil getting to 89- 90 degrees celcius can take a good 20 miles.

So if you only do 25 miles then stop, and then do 25 miles back home, you can not really expect 50mpg.

maybe 35-40 mpg going and 35-40 mpg going back.

Everyone drives different tho, obviously.

If you are running hot and the first 5 gallons gave you 48 mpg (240 miles)

& the light shows or flashes when the engine is hot and doing good MPG, there will be 3 gallons in the car still.

(if it was brimmed, 2 gallons if not filled till you see it)

Safely you can do 60 miles, and then start looking to hypermile to get fuel.

If 97, 98 or 99 RON makes no difference then why use it,

but Sainsbury's Super 97 RON was cheaper than everyone elses 95 RON, so it seemed stupid to me not to buy it when i have always found it good.

Aberdeen was pence a litre below everywhere else for a couple of weeks.

george

[Dizeee]

I agree on the 1.0 not needing the 98RON fuels. I've tried it 3 times in a row to make sure but I actually got less MPG than standard fuels. I'm getting around 350miles until the bar starts flashing - I try to fill up asap as I'm unsure how far I'll get with the bar flashing. If Dizeee's calculations are correct that will see me around 430miles?

Usually takes £35 to fill from flashing last bar & i try hard to go easy on the gas. Occasional blast but thats only a few times on a tank!

If your bar doesnt start flashing until 350 then you will easily get 420 from a tank.

[aaronfife]

Arron

part of the thing is if you set off from a cold start even at this time of the year and ambient temp and drive for 15 minutes your engine is only just up to optimum running temp, coolant is quick but oil getting to 89- 90 degrees celcius can take a good 20 miles.

So if you only do 25 miles then stop, and then do 25 miles back home, you can not really expect 50mpg.

maybe 35-40 mpg going and 35-40 mpg going back.

Everyone drives different tho, obviously.

If you are running hot and the first 5 gallons gave you 48 mpg (240 miles)

& the light shows or flashes when the engine is hot and doing good MPG, there will be 3 gallons in the car still.

(if it was brimmed, 2 gallons if not filled till you see it)

Safely you can do 60 miles, and then start looking to hypermile to get fuel.

If 97, 98 or 99 RON makes no difference then why use it,

but Sainsbury's Super 97 RON was cheaper than everyone elses 95 RON, so it seemed stupid to me not to buy it when i have always found it good.

Aberdeen was pence a litre below everywhere else for a couple of weeks.

george

I only used +RON to see if it did make a difference. Which obviously it didn't. I travel 18miles to work and can reassure you I get 55-60+ mpg from every tank. As you say, I do drive it like a old woman but yes it does take 10-15min for coolant to fully get up to normal operating temperate.

It's good to know I'll be good for over 400miles.

[tarquin]

The fuel gauge does not seem to function the same on each refill. I never rely on it. I have had times when from full it has returned 152 miles and the first block has gone followed by the second 5 seconds later!!! Also its generally accepted you have a minimum of 50miles when the last block flashes. Well mine did 23 miles and came to a halt. Run out of fuel. So now i have to re-fuel without fail as soon as the last block flashes I use trip A just to make sure i'm averaging 280-300 miles a tank and thats it. It is totally unrelyable.

David

[wornout]

I have never had the courage to run my car for long after the flashing block starts, however, the last time it flashed I travelled a further two miles and filled the tank which took 25.35 litres and I had done 238 miles so presumably I had enough fuel to go a further 50 odd miles. That is reassuring.

[atkiman]

it is a truly awful fuel guage. never gives the same mileage per block reading. my first block seems to go between 100 and 135 mls, but it has gone out at 90 before now. i have noticed the longer the first one stays on , the quicker the second one goes out, sometimes the second is only on between kettering and cathorpe.

[DazIQ]

Agreed - fuel gauge is poor. Mine actually started going back up yesterday - on 2 bars then when I looked again it was 3 bars.

[atkiman]

yes , i've had that one too.got home on 2 bars , next morning 3. i got more accurate readings 30 years ago with a wooden stick

[s44gtw]

How people are annoyed by the fuel gauge amuses me.

You just put in petrol and you know how much because you are holding the trigger and then going to pay for it,

either fill or say 10 litres just.

Zero the Mileometer and drive.

allow yourself to use the simple arithmatic of 10 miles for a litre about covers it if driving normally, or you know if you use more because you drive regularly surely.

If the petrol is getting towards being low then go buy more, or if in the sticks carry a 5 litre safe fuel can securely.

seems so simple.

not like you have 2 belly tanks and 2 more reserves and 1000 litres to worry about surely.

350 miles and you need petrol again or not seems simple.

george

[tarquin]

To be honest George, I understand what you are saying,but the gauge should not act in the erratic way it does. Once it had gone down to a level, it shouldn't go back up again. Visually it is meaningless. You have to remember how much of the of the segment showing, you previously used when getting into the car. Example. I get in the car, and start it, i am seeing the last 2 segments.I need to go 70 miles.2 full bars should give me something like 100miles. I drive 5 miles and one segment goes and the last is flashing. now i know from past experience that will give me anywhere between 23-50 miles. So what i initially think will take me 100 miles, i could be down to 28miles.It should not also reassess the fuel to a different level it had assessed before you stopped. Also it should not loose a segment then 10 seconds later loose another one which has happened to me. The real problem is the segments are far to big and should be divided into much smaller ones to act more like a analogue indicator. You should really only have to glance at the gauge and mentally know how much and how far you got left. you shouldn't have to reset the trip and monitor the 350miles unless you want to check your MPG

David

[johnan]

To be honest George, I understand what you are saying,but the gauge should not act in the erratic way it does. Once it had gone down to a level, it shouldn't go back up again. Visually it is meaningless. You have to remember how much of the of the segment showing, you previously used when getting into the car. Example. I get in the car, and start it, i am seeing the last 2 segments.I need to go 70 miles.2 full bars should give me something like 100miles. I drive 5 miles and one segment goes and the last is flashing. now i know from past experience that will give me anywhere between 23-50 miles. So what i initially think will take me 100 miles, i could be down to 28miles.It should not also reassess the fuel to a different level it had assessed before you stopped. Also it should not loose a segment then 10 seconds later loose another one which has happened to me. The real problem is the segments are far to big and should be divided into much smaller ones to act more like a analogue indicator. You should really only have to glance at the gauge and mentally know how much and how far you got left. you shouldn't have to reset the trip and monitor the 350miles unless you want to check your MPG

David

I can understand you not liking going to dealerships for work on your car, David, but as I have mentioned before there is a modification to the fuel filler pipe/sender unit that is designed to make the gauge readings more consistent.

I had it done to my first IQ and it certainly helped.

If yours is so bad it might be an idea to ask about it!

(Of course "they" will deny a mod exists and say "they are all like that", but I assure you it is an accepted fault and a modification has been produced.)

John

[tarquin]

Hi John

Can you tell me how the filler pipe sender has changed the way the display functions for you. I still see that a segment is too large for you to get a realistic idea of how much fuel you have left plus they are not linear, The first could give you 100 mines whereas the 3rd could give you 50 miles . The thing is supposing i left the car with 2 segments visible, and they have been for say 35miles and my wife gets in it the next day, she has 35 miles less than than possible she thought she had. and if I, or she had not reset the trip, she has no real idea how much fuel she has left. or when its going to drop to a flashing segment . Basically you can't divide the gauge into 4 segments and get a, even near idea of what the fuel is doing. Get into my Peugeot 406. Instantly if it shows a quarter of a tank i have 150 miles left.Digital interpretation Rubbish

David

[tarquin]

On getting in the car and taking a snapshot af an instance in time, you cannot tell how much fuel / miles you have left in your tank without reference to the trip computer. And thats wrong

David

[johnan]

David, it has been at least two years since I had the fix done and all I remember was that before it the gauge reading was completely erratic and couldn't be relied on at all, and after the fix it was "quite" accurate.

I think the filler pipe may in some way be connected to the sender unit so to change the unit the pipe needs to be changed too, but I may be wrong.

I think the problem with the sender unit was found to be faulty manufacture, ie a badly made batch not up to spec. by a third party supplier, rather than a design fault.

John

[tarquin]

Hi John

I will investigate the mod this coming week. The way i see it is if you have a segement illuminated it has a range of up to 100 miles. At any instance you cant tell how far along that range you are. It needs a different display with finer increments. At present it is just as good as an on/off switch

David

[atkiman]

hi george

you're spot on, thats exactly what i do , know what mpg i'm doing (manually,calculator, acch top up) ignore the fuel guage and go on the miles,

never had the luxury of a belly tank, just twins, and my trusty stick.

[tarquin]

Thing is the trip computer and visual fuel display are for 2 diferent reasons. If you have to reset the trip at each tank fill up ) which is what i also have to do) then the visual display is redundant. Will post a couple of pic's later that i took today of my fuel gauge which dropped 2 segements after only 12 miles!!

David

[tarquin]

Here are 2 pic's i took yesterday as you can see within the space of 12 miles the display has lost 2 segments. visually it is of no use at all. Which is wrong

David

[Mr Jones]

visually it is of no use at all. Which is wrong

Totally agreed. I've owned my iQ for a month now and everything is great apart from the silly digital guage. I miss my trusty analogue. My last 'full tank' gave me 300miles before it starts flashing - 27.86L filled up to the brim.

Will now have to use my 'Trip B' to monitor my last fuel up instead.