Thoughts about the Fuel Gauge?

[First Ever Audi]

Thought i would put this one out to see how you folks are getting on with the LED fuel gauge, how it changes and how it represents fuel remaining.

Example:

Fuel tank is 50 L. At the weekend, 2 out of LED were out, theoretically representing 1/4 tank used with 3/4 remaining. So you would think that the tank would take around 12L to top up......22L later it was full....and considering its a 50L, tank this is what you would expect from half tank...

I don't have any issues with the MPG or fuel costs and if i want to see the range i just use the Efficiency program....i am just slightly confused by the LED's and what they represent. I've done maybe 150 miles since fueling and as yet, none of the LED's have gone out, which of course doesn't match with the distance to empty.

Just wondering if anyone else has the same comments.....just out of interest

 

[Schizophonic]

I would like the leds to be more fine or smaller bars than the current version. It's difficult to judge at the moment snd I've only refilled a handful of times where in my old car I know how much I can drive on (old needle type)

Suppose it's getting us to it, but anyone tried to get to 0 on the computer and continue running their car?

 

[mjcourtney]

Yes I've noticed this too. The lights don't really accurately represent the percentage of fuel left. At the opposite end of the scale my fuel light came on last week and I put in just £20 worth of fuel, and the needle shot up to over half full, yet I'd clearly added only around 1/3rd of a tank of fuel. In my experience this means the fuel gauge takes forever to drop the first digit, but then rapidly drops after the 2nd or 3rd LED has extinguished, almost a logarithmic scale!

 

[Croftj]

Must admit i noticed that when i had a test drive for the weekend. I think like any car, it can take a while to get used to how the fuel gauge goes down with the tank. For example my 8P diesel stays 100% full until about 100-120 miles then slowly starts to come down. I've got used to this over the years.

What about the trip computer? does that not effectively make the fuel gauge a bit redundant anyway?

 

[cemerson]

My current car does the same thing (though has 16 LCD segments to represent it rather than 8) - stays showing 'full' for quite a while, then starts to drop. Even at the low end it does this - shows empty when there is quite a bit left. It's like there is a margin at each end and the guage only measures the 'middle' bit.

 

[Coxy234]

I would like the leds to be more fine or smaller bars than the current version. It's difficult to judge at the moment snd I've only refilled a handful of times where in my old car I know how much I can drive on (old needle type)

Suppose it's getting us to it, but anyone tried to get to 0 on the computer and continue running their car?

With my demo car I did manage to get it to 0 and continue for a further 8 mile back to the Audi Garage, I was slightly nervous and ran in eco mode all the way back. Not good when all you want to do it wack it in dynamic and test the engine

 

[cemerson]

You can do about 50 or 60 miles on an "empty" tank in my car!

 

[JohnM100]

Interesting thread as I have been a curious how I would get on with this too (build week 36).

Cemerson - if you can do 50+ miles from the gauge showing empty then not only is the gauge limited in terms of only being able to show 8 levels it can show but also supports the idea that it seems to measure "middle of the tank".

With the 8v having a slightly smaller tank (50L) than previous it does suggest those (like me) who go from full to vapour will be filling up more frequently as there is more guesswork when the tank is running low and off the gauge.


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[cemerson]

Cemerson - if you can do 50+ miles from the gauge showing empty then not only is the gauge limited in terms of only being able to show 8 levels it can show but also supports the idea that it seems to measure "middle of the tank".

This is on my current car - I don't have my A3 yet.

 

[Daveotto]

I am confused by all this, or is the sun getting to my head whilst on holiday.

Petrol gauges, dial or LED, have never been that accurate and will nearly always differ slightly car to car. My current 8P has A driver information Display and I can toggle through the trip computer and get miles to empty, in addition I get refuel warning light approx 50 miles to empty which is pretty accurate as I have taken it to less than 10 miles and filled up with nearly 55 litres(bigger tank on 8P).

i am assuming the new car will display the same via the DIS and/or MMI rendering the fuel gauge useless, which in effect is what it has been on my current 8P, that is I rarely ever look at it.

 

[JohnM100]

I do see your point daveotto but on my current A3 with analogue needle I have learned over time that:

Needle hardover = full or within 5 litres
Full = ~8 litres used
3/4 dial = 2/3 full
2/3 dial = 1/2 full
Etc...... And down to
bottom of red = ~52 litres.
25 miles after DIS states 0 but wouldn't risk further.
.....and all the estimates in between.

DIS and miles to empty is also vague and seems to accelerate between a stated range of 190 miles at a stated half full when in reality it is nearer 120 miles.

I don't think anyone is expecting absolute accuracy. I had a Rover 200 back in '96 (no digs please) that showed empty when it still had 1/3 tank.

.....but with a gauge there are all the ranges in between the markers and not just the 8 LEDs.



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[First Ever Audi]

Lots of good discussion chaps that's the best thing about this forum!

 

[cemerson]

I'm pretty sure when I had an 8P company car, although it had a dial, it was digitally driven and still went in 'steps', so just as accurate really

 

[jet_andy]

There's a big safety margin built into the gauges around minimum and with the 'miles to go calculation', because one thing you really do not want to do is run a diesel out of fuel. And I doubt they'd have a differently calibrated gauge for a petrol.

 

[Daveotto]

I'm pretty sure when I had an 8P company car, although it had a dial, it was digitally driven and still went in 'steps', so just as accurate really

my 8P is analogue

 

[karlabdool]

I added 26 litres of fuel with 2 blocks lit on the fuel guage and it lit up all the way with only a single (top) block unlit.

 

[ukm_1]

Must admit that within 2 weeks of getting my 8V TFSI I ran the tank empty and had to get a can of fuel bought out by a work colleague :Flush: That was within 15 miles of the DIS showing 0 miles, my previous A5 would get over 30 after 0 although I never ran out in that!

Moral of the story - don't let it get too low

 

[dieseldoug]

You can always ask the dealer to adjust the float to calibrate the gauge for you but this won't be done under warranty unless its way out. The good thing is it won't run dry at empty on the gauge, but how many people a actually over fill their cars as in fuelling up to the neck as this is not counted in the gauge. Access to the sender may be hard and having to drop the tank but its easy done if you know what your doing.

 

[Dylock]

Don't forget that the top of the gauge will always last longer, due to the filler tube, which in some cases hold a fair amount of fuel.

 

[glamic26]

I have also been annoyed by this. I filled the tank up last weekend before 90 mile drive to Sheffield and back. When I left the 'miles left' was at 450. When I arrived 90 miles later it was at 455 and the tank was still showing full! When I got back it was at 410 and the fuel gauge had lost just 1 bar from 8. Naively I took this to mean that after 180 miles if I had 410 left I would do around 590 on that tank. However after the fuel gauge dropped below half (at around 270 driven and showing 260 remaining, so pretty much half on those stats) the miles left dropped about 10 miles for every 5 I drove and the bars on the fuel gauge went down far quicker. The 'please refill' came up at 400 miles with an estimated 50 remaining! Not overly useful I found! I reckon I am on half a tank left when only the first two bars of the fuel gauge are gone.

 

[First Ever Audi]

It's a challenge isn't it!

 

[dieseldoug]

Glamic26

It may be worth checking after a 100 mile run again against fuel used from full tank that will see how far out you are, but fill the car using the gauge and not to the neck. This may help the confusion in the tank to miles and the opposite on the last 2 bars it's 50 litre tank see what intakes to refil then you can work out what the neck holds, I bet this may be 3-5 liters.

Doug

 

[hittchy]

Never found it to be a problem to be honest. When it's empty I fill it and then drive until the light comes on again. The variations in between are pretty much irrelevant to me.

As Davotto said though, I tend to use the DIS to plan if I have enough for my journey. It does vary in mileage estimated though depending on how the car is driven (which it should).

 

[deci]

Same here. It's not a problem at all for me. Just use the computer readout which is more reliable.

 

[Daveotto]

Never found it to be a problem to be honest. When it's empty I fill it and then drive until the light comes on again. The variations in between are pretty much irrelevant to me.

As Davotto said though, I tend to use the DIS to plan if I have enough for my journey. It does vary in mileage estimated though depending on how the car is driven (which it should).

i have found the DIS on my 8P to be pretty accurate if I am driving in my normal style to and from work or on regular journeys. Where it fouls up is if you change you styles from driving like grandpa and then driving like a boy racer. At the end of the day it estimates your range/miles to empty based on your most recent driving style so if you want to prove it wrong it's pretty easy.

 

[dieseldoug]

Same here if it needs fuel then fill it up, never really drive for the MPG figures I just drive it to enjoy it quite happy to have 30 MPG that means I have nailed it.

 

[mxnrg]

I think a 8 part LCD gauge would annoy me compared to an analogue dial but as others have said I guess you'd get used to it. I'm from the fill it up when it enters the 'red' school of thought, so would probably fill when down to 1 block as a rule.

Slightly off topic but, since the S3 has the turbo boost pressure gauge using the 8 part LCD fuel gauge on the A3, I wonder where you get the fuel levels on the S3?

 

[97catalunya]

Slightly off topic but, since the S3 has the turbo boost pressure gauge using the 8 part LCD fuel gauge on the A3, I wonder where you get the fuel levels on the S3?

That's a very good point!

 

[f1nny]

Slightly off topic but, since the S3 has the turbo boost pressure gauge using the 8 part LCD fuel gauge on the A3, I wonder where you get the fuel levels on the S3?

The fuel gauge on the S3 is on the side with the Speedo, same as the A3. On the S3 they have just replaced the engine temperature gauge with a boost one, if it overheated it'll probably have the red temperature warning come up on the DIS.

 

[97catalunya]

The fuel gauge on the S3 is on the side with the Speedo, same as the A3. On the S3 they have just replaced the engine temperature gauge with a boost one, if it overheated it'll probably have the red temperature warning come up on the DIS.

That's a shame, you would think with a performance car they would add dials for extra drama and theatre, even if it was an extra screen on the MMI like they do on the Japanese cars.

 

[Daveotto]

That's a shame, you would think with a performance car they would add dials for extra drama and theatre, even if it was an extra screen on the MMI like they do on the Japanese cars.

all part of the understated quality that goes with the brand, even the R8 has the standard dial and gauge arrangement

 

[97catalunya]

all part of the understated quality that goes with the brand, even the R8 has the standard dial and gauge arrangement

Yeah I suppose your right but still a shame though. I think the dash is beautiful and uncluttered, but just a bit of software on the MMI with analogue style gauges to show boost pressure, intercooler temp etc would add drama. Add an analogue style fuel gauge too would solve another issue

 

[mxnrg]

The fuel gauge on the S3 is on the side with the Speedo, same as the A3. On the S3 they have just replaced the engine temperature gauge with a boost one, if it overheated it'll probably have the red temperature warning come up on the DIS.

Yep, just read a review and realised they had used the temp gauge not the fuel one, oops.

 

[glamic26]

I've watched this last tank very carefully and here is when each of my 8 bars disappeared.

1=130miles
2=185miles
3=220miles
4=270miles
5=315miles
6=365miles
7=400miles
8=440miles.

With the exception of the first bar most seem to be fairly consistent (35-55miles) although with it being the same type of driving for the whole tanks I don't understand why there is still a 20mile difference in some.

The 130miles for the first bar still annoys me though as it makes the whole bar system pointless. When my fuel tank is showing 1/8 empty it has actually used 30% of my mileage! I just don't understand how with 21century sensors this isn't accurate to the millilitre! Or it could at least have some sort of learning built in to the computer. For example it knows on average I can do 440 miles to the tank (or until the last bar starts flashing) and so on the next tank it should assume that each bar is worth 55 miles!

 

[jet_andy]

The sensor will be accurate - it's just the electronics that has to split it into only 8 segments rather than show on an analogue gauge.

Personally I don't have much of an issue, I always fill my tank, and will do it as convenient when on the last one or two segments. What it reads between full and empty don't really matter - the computer will give rough miles left in tank anyway - which of course is based on the current mpg - averaged over a short period.

 

[First Ever Audi]

I followed your example for only 2 bars and got identical results:

1=130 miles
2=182 miles

I filled it to brim just as the 2nd bar dropped and it took 18.75 Litres. I suspect as Diesel Doug suggested a while ago that the reason for getting so many miles from the first bar is to do with the amount of fuel in the neck..I managed 185 Miles from the 18.75 L so i'm very happy with that...incredibly saving £20 per month on fuel compared to my Mondeo Diesel