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Model specific boards => Golf mk7 => Topic started by: Geomets on 12 January 2014, 16:25

Title: Fuel gauge accuracy
Post by: Geomets on 12 January 2014, 16:25
I didn't join the forum for a week as I was driving my new GTI. Everything is good except two things (unfortunately). The first is the noise of the front-left suspension. -The Masters at the garage said that it should be louder so they can identify the type and the source of the noise (complete idiots).
The second problem is more complicated than it seems, as it has to do with the fuel gauge... So, I took delivery with a completely empty tank, the gauge did not move at all so I "crawled" to the fuel station across the road. I filled it up, took 50lt (on a 50lt tank!), gauge went straight to full. On a little excursion I made afterwards, the gauge would still show full for the next ~100km! I made a good amount of kms, the gauge showed a little less than a quarter of a tank (the red area and the almost all the white one above it), the range was at 90km(!) and in the fuel station it swallowed a good 43lt!!! According to the manual, the reserve capacity is 5lt of the 50lt tank. I, of course , went to the dealer but the Masters (yeah, sure) there told me it's fine(!!!). I made 520km since then, now I'm in a 90km range (consumption since refueling is 8.3lt/100km and long-term is 8.6lt/100km) and the gauge shows the dash under the quarter (I refer to the first white area). The range seems ok, but the accuracy.... So, after that enormous, boring post, can I ask you respected members what is the fuel quantity if the gauge is in the first quarter on your GTIs? Please, give me a clue. Thank you very much in advance.
Title: Re: Fuel gauge accuracy
Post by: Gingernick on 12 January 2014, 16:31

in my current car it seems to use hardly anything for a while but as soon as it gets to halfway it seems to empty quicker

i often wonder if its to do with irregular shaped areas they squeeze the tanks into?
Title: Re: Fuel gauge accuracy
Post by: 2014GTi on 12 January 2014, 16:31
I think the fuel guages are always top heavy and my Polo was the same.
I find that I do far more mileage towards the upper range of the gauge than the lower but I generally find the GTi economy really good.
I get around 40mpg on my commute to work but this does include a large stretch driving at 50mph.
Title: Re: Fuel gauge accuracy
Post by: karlak on 12 January 2014, 16:49
http://autos.aol.com/article/gas-gauge/


Some reasoning behind the fuel gauge setup.
Title: Re: Fuel gauge accuracy
Post by: Geomets on 12 January 2014, 16:52
The economy is great for the type of the car. But what is the exact amount of fuel left when it is in the first quarter? Or, how much fuel do you get when you refuel whilst the gauge is in the first quarter?
Title: Re: Fuel gauge accuracy
Post by: monkeyhanger on 12 January 2014, 18:43
My gauge is far less top heavy than any other VW I had before it. When I fill up to the 1st click, the needle can move off full within 20 miles, generally reads around 120 miles done at 3/4, 225 miles done at 1/2 and when it hits the red, the car is reading about 370 miles done. My overall range to empty on the MFD is generally about 430/440 miles. Only the last 40 miles seems a bit screwy on the gauge.

Anyone finding it very top heavy, are they filling to 2nd click and maybe squeezing another 1.5L more than a 1 click fill?
Title: Re: Fuel gauge accuracy
Post by: GrahamFR on 12 January 2014, 20:56
First half always goes down slower than last half. One of the reasons is the fuel that's in the pipe leading to the tank is full but not measured, so in theory you have more than a full tank if you brim the tank
Title: Re: Fuel gauge accuracy
Post by: Sootchucker on 12 January 2014, 22:06
Mines the same as MH. Seems much more linear then any VW I've owned before. My Scirocco would do about 50-60 miles without budging from full, then about 270-300 miles to half then plummet like a stone.

As MH said, within 25 or so miles mine is already starting to move off the full mark, about 240-265 miles to half the about 420-430 miles before the light comes on (so I guess about 470-480 total taking into account the reserve). Seems much more accurate.
Title: Re: Fuel gauge accuracy
Post by: corgi on 13 January 2014, 08:43
Fuel gauge is only a rough indicator of the amount of fuel you have available. As the gauge moves lower I tend to look more at the range available as this is calculated on your recent fuel consumption

There appears to be nothing much wrong with the car - your average is 32-34 mpg which seems reasonable to me for a GTI in general driving.
Title: Re: Fuel gauge accuracy
Post by: GTI7me on 13 January 2014, 10:10
I'm not convinced the tank in the GTI is 50l. I filled up the other day with a 25 mile range and i put 50.7l in to it  :huh:

J
Title: Re: Fuel gauge accuracy
Post by: GrahamFR on 13 January 2014, 11:01
I'm not convinced the tank in the GTI is 50l. I filled up the other day with a 25 mile range and i put 50.7l in to it  :huh:

J

Tank plus pipes?
Title: Re: Fuel gauge accuracy
Post by: monkeyhanger on 13 January 2014, 11:02
I'm not convinced the tank in the GTI is 50l. I filled up the other day with a 25 mile range and i put 50.7l in to it  :huh:

J

Or you were didled at the pumps. You must have been running on fumes otherwise.

I once took the “How far can you go?” thing too far in my first Scirocco and it cut out about 100 yards away from the petrol station I was going to fill up at. It was a flat road, and that 55L tank took 55.7L to fill to first click. Unless the 50L tank is designed any differently, the only spare is the filler neck.
Title: Re: Fuel gauge accuracy
Post by: GrahamFR on 13 January 2014, 11:06
I'm not convinced the tank in the GTI is 50l. I filled up the other day with a 25 mile range and i put 50.7l in to it  :huh:

J

Or you were didled at the pumps. You must have been running on fumes otherwise.

I once took the “How far can you go?” thing too far in my first Scirocco and it cut out about 100 yards away from the petrol station I was going to fill up at. It was a flat road, and that 55L tank took 55.7L to fill to first click. Unless the 50L tank is designed any differently, the only spare is the filler neck.

Where is the tank positioned on the mk7? Also, did you have to bleed some fuel to get it to start again or did it fire up fine once you put filled her up? If its the latter I suspect like most modern diesels it will cut off but reserve some fuel so that you dont have to bleed the pipes to start again.
Title: Re: Fuel gauge accuracy
Post by: monkeyhanger on 13 January 2014, 11:48
I'm not convinced the tank in the GTI is 50l. I filled up the other day with a 25 mile range and i put 50.7l in to it  :huh:

J

Or you were didled at the pumps. You must have been running on fumes otherwise.

I once took the “How far can you go?” thing too far in my first Scirocco and it cut out about 100 yards away from the petrol station I was going to fill up at. It was a flat road, and that 55L tank took 55.7L to fill to first click. Unless the 50L tank is designed any differently, the only spare is the filler neck.

Where is the tank positioned on the mk7? Also, did you have to bleed some fuel to get it to start again or did it fire up fine once you put filled her up? If its the latter I suspect like most modern diesels it will cut off but reserve some fuel so that you dont have to bleed the pipes to start again.

No bleed/purge required, it cuts off before it lets air in the system. If I had 25 miles left on my MFD, I would end up with a 46L fill, or thereabouts.
Title: Re: Fuel gauge accuracy
Post by: GrahamFR on 13 January 2014, 12:39
I'm not convinced the tank in the GTI is 50l. I filled up the other day with a 25 mile range and i put 50.7l in to it  :huh:

J

Or you were didled at the pumps. You must have been running on fumes otherwise.

I once took the “How far can you go?” thing too far in my first Scirocco and it cut out about 100 yards away from the petrol station I was going to fill up at. It was a flat road, and that 55L tank took 55.7L to fill to first click. Unless the 50L tank is designed any differently, the only spare is the filler neck.

Where is the tank positioned on the mk7? Also, did you have to bleed some fuel to get it to start again or did it fire up fine once you put filled her up? If its the latter I suspect like most modern diesels it will cut off but reserve some fuel so that you dont have to bleed the pipes to start again.

No bleed/purge required, it cuts off before it lets air in the system. If I had 25 miles left on my MFD, I would end up with a 46L fill, or thereabouts.

So your saying 25miles is roughly 5litres? So you get 5miles per litre? Seems a bit low, that's only 250miles per tank
Title: Re: Fuel gauge accuracy
Post by: GTI7me on 13 January 2014, 12:51
It fired up as normal. The gauge wasn't right down either. Wondering whether it's actually 55l?

25 mile range would equate to around 5l left in the tank.

J
Title: Re: Fuel gauge accuracy
Post by: monkeyhanger on 13 January 2014, 13:30
GrahamFR: I’m sure the 5L @ 25 miles left is just a bit of built in caution by VW – enough to give you an extra 20/25 miles beyond the MFD reading zero miles left. When my 1st Scirocco choked up I had gone about 20 miles past “zero” – it was well known to have a bit beyond reading empty and I was carrying a 5L canister of Diesel at the time. I’d forgotten to bring my wallet when I intended filling up the day before.
Title: Re: Fuel gauge accuracy
Post by: Geomets on 13 January 2014, 17:24
I read in an other forum that it the gauges are made to act like this because statistics say consumers like the gauge to drop slightly. So we asked for the gauges to act like this (not me if you ask me, I'm the minority, I love accuracy). And these were words of a Ford technician. Today I trade a test. I left the car without refilling until I got just below the First quarter and just above the red zone. In 50km range it showed an orange pump in the MFD. I don't know if there would be another light if I actually got to the red zone, but I can confirm that I filled it with 47lt. As for the range, I refilled at 40km, but that's hardly the case, as my long-term is 8.7lt-100km and since start/refueling were at 8.3lt/100km.
So, VW says there are 5lt reserve, but I say there are 2.5-3lt. I took delivery of the car with the gauge not moving at all and 0km range. It took 50lt of fuel.
Title: Re: Fuel gauge accuracy
Post by: eatontrifles on 01 June 2017, 14:30
Bumping a 3 year old thread as it seemed relevant.

I filled up the GTI with 51.36l of fuel today - the range was at 0 miles (had been for around 3 miles) and as far as I can tell from the displayed fuel gauge it was at the bottom. The quoted tank capacity is 50l, so how have I put almost 1.5l more in? I always stop fueling after the first click, let it settle then go again until the second click.
Title: Re: Fuel gauge accuracy
Post by: dubber36 on 01 June 2017, 14:39
Fuel tanks are generally a little larger than stated. Also there is the volume of fuel in the filler neck. It will hold 'at least' 50 litres, just like a packet of crisps will have a minimum content of x grams.
Title: Re: Fuel gauge accuracy
Post by: kelvyn29 on 01 June 2017, 14:52
I'm not convinced the tank in the GTI is 50l. I filled up the other day with a 25 mile range and i put 50.7l in to it  :huh:

J

Tank will be 50 litres but then factor in the hoses etc this will give you more than the stated tank capacity.
Title: Re: Fuel gauge accuracy
Post by: eatontrifles on 01 June 2017, 15:33
So if I managed 51.36l, how much did I have left?
Has anyone actually run out of fuel and then brimmed the tank to get the true capacity?
Title: Re: Fuel gauge accuracy
Post by: phazer on 01 June 2017, 21:27
There is a one gallon reserve on top of the tank capacity. So to run out you really really have to try  :grin: that's why 50l on a less than totally empty is do-able.