Full tank gives 180miles

Apr 7, 2021
3
1
So i purchased Ibiza a few weeks ago and everything was going good until i realised that when i topped up a full tank it only gave me 180miles on the dashboard. First i thought this was an inaccurate reading but it turns out its pretty accurate as the last time i topped up an amount it predicted 70 miles and gave 80. So pretty close. I took the car to a garage to check this out because full tank should be 300+miles. But the mechanic found nothing under the diagnostic machine and doesnt want to syart taking things out unnecessarily.. In going to try fuel injector cleaner but im not hopeful for this. Does anyone have any idea what could be wrong.
 

vw.man

Active Member
Apr 17, 2020
11
3
What engine size, petrol or diesel; have you actually driven the car until it runs out of fuel? I'm not sure what you mean by "topping up" when you say one time it told you 180 miles range and then another time it said 70 - are you saying you brimmed the tank on both occasions? Did the fuel gauge read full? What MPG are you getting per the display, and what is your calculated MPG (full tank to full tank)?

I suggest driving the car until it runs out of fuel or you get to the range you expect - fill up a spare can and stick that in the boot. See how far you get. If this shows you have normal range then personally I'd just live with it. It's probably just a dodgy sender unit or a fault in the gauge: I can't imagine an engine fault would make the car burn through double the normal fuel, especially if nothing came up on diagnostics.

FWIW my 2009 1.4 petrol Ibiza usually gives a range of around 400 miles when full to brim. It usually averages around 45mpg on runs of about 40 miles / mixed driving.
 
Apr 7, 2021
3
1
My engine size is 1.4. its petrol. So to rephrase.

I bought the car with some fuel in it. Topped up about £10 worth of fuel. Didnt take notice of anything. Then i bought another £15 worth of fuel and at this point i was wary of the mileage as it said i had 70 left on the dashboard (predicted) i thought this would just be a rough estimate and maybe lowered due to me having some unpolished driving as im quite new to it. I recorded my mileage before driving off from the petrol station, and then just as i nearly finished that amount of fuel i recorded it again and it was a difference of 80miles on the actual mileage counter. I then full tanked the car which was about £50 and then the dashboard predicted 180miles. Im assuming this would be near accurate as it was the last time as just discussed. Ive recorded the mileage and intend to finish this tank and see the difference. But im not hopeful. Will try some redex fuel injector cleaner tmrw and see how that goes.
 

vw.man

Active Member
Apr 17, 2020
11
3
If you only get 180 miles when you finish your current full tank (and I guess you'd have to let it run out rather than trust any of the instruments just to be sure) - then I'd be going straight back to the seller as this would clearly be a pre-existing fault that the seller must have known about.
 

rafletcher

Active Member
Feb 18, 2021
92
38
If the car is running that rich, you would normally be able to smell the unburnt petrol from the exhaust even with the car up to temperature. The simplest thing, if you do prove that it's running rich/has poor mpg and it's not just an instrument thing (top up the tank, drive 100 miles, top up tank and manually calculate the consumption) is to get the MAF (mass air flow) sensor changed (it's one thing that's used to decide how much fuel ius needed to the injectors). These can deteriorate and not cause any warnings.
 

KXL

KXL
Dec 15, 2016
1,499
169
London, UK
When you next fill up, recommend you fill it up with Shell/Esso's finest 99RON fuel just for 1 tank, go for a drive circa 40-50mph constant speed A roads for 10-15 mins, would the fuel remaining increase? It's possible the most recent trips with the car was very short and very slow, mainly moving it infrequently. What's the long term mpg on it?
 

SRGTD

Active Member
May 26, 2014
1,260
570
It's possible the most recent trips with the car was very short and very slow, mainly moving it infrequently. What's the long term mpg on it?
Yes, journey type / length and volume of traffic on the roads are significant factors in relation to the mpg achieved. If the OP is mainly driving at peak times in heavy traffic on short journeys with lots of stop start work on a cold engine, then those conditions will have a major detrimental impact on mpg.

@TharakMiah; how recently have you checked your tyre pressures? If they’re under inflated, that will also be having a negative impact on your fuel consumption.
 

andycupra

status subject to change
the predicted range is typically based on recent driving. so if you have done a couple of short drives, then the predicted range will plummet, but if you go for a longer drive then you may find the predicted range increases.. hope that makes sense.
Often if you check range at the end of a journey you will find it looks ok but you are unlikely to get that as its based on the last few miles when you car was fully up to temperature. whereas check it a mile after starting when the car is cold it may predict a shorter range as the current mpg is poor.
 

SRGTD

Active Member
May 26, 2014
1,260
570
the predicted range is typically based on recent driving. so if you have done a couple of short drives, then the predicted range will plummet, but if you go for a longer drive then you may find the predicted range increases.. hope that makes sense.
Often if you check range at the end of a journey you will find it looks ok but you are unlikely to get that as its based on the last few miles when you car was fully up to temperature. whereas check it a mile after starting when the car is cold it may predict a shorter range as the current mpg is poor.
@andycupra; Makes perfect sense to me.

@TharakMiah; if you manually calculate your overall fuel consumption over a few tank fulls of fuel, that should give you a pretty accurate view of your long term mpg.
  • Make a note of your mileage at the start of the monitoring period.
  • Each time you fill up make a note of the mileage, fill the tank to the brim and make a note of the number of gallons of fuel taken to fill the tank.
  • Keeping a record of the number of gallons of fuel used and miles driven each time you fill up will enable you to calculate your mpg a) per tank full b) overall for all tank fulls.
Alternatively, there are various apps that you could use if you want to keep track of your fuel consumption on a longer term ongoing basis;

 

dm222

Active Member
Dec 7, 2013
1,312
25
If you just do city and short travels I would not be surprised

In this engine you dont spend a cent in problems but you spend more in fuel.

I prefer this way to be honest
 

vtxracer

Active Member
Jul 25, 2009
399
11
Greece
Fill it up, do some highway driving and see how that goes. It really depends on driving conditions. In very heavy traffic I would be happy if I got 180 miles out of 2 tanks ! 🤐
 

SRGTD

Active Member
May 26, 2014
1,260
570
Fill it up, do some highway driving and see how that goes. It really depends on driving conditions. In very heavy traffic I would be happy if I got 180 miles out of 2 tanks ! 🤐
^This.

To just be guided by the car’s calculated figure for distance / range remaining in the tank as an indication of how good or bad a car’s fuel consumption is - as the OP seemed to be doing - isn’t a good way to assess whether or not there’s anything wrong.

@TharakMiah; lots of good advice has been provided in this discussion thread to help you understand and monitor your car’s mpg figures. Would be interested to hear the outcome, once you’ve had an opportunity to put some of the suggestions into practice.
 
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