[eye30]

My new i30 has a "bar" fuel gauge and to be honest I'm not a big fan of it.

Give me the needle gauge any day.

What I am finding is when it is on 3 bars it seems to be there for loads of miles, about 50 plus.

When on 2 bars it seems to drop to 1 bar after about 20 miles.

As soon as it drops to 1 bar the low fuel light comes on but I'm not sure how much fuel is left. 

Yesterday in all the rain etc I was stopped on the motorway, due to accident further along, and while at tickover 1 bar appeared and the low fuel light came on.

I was only 5 miles from home so not a problem as I would expect there to be at least 1 gallon, 4.546l.

Anyone else with the "bar" gauge got any views on how much is left when the low fuel light comes on?

[AlanHo]

I did a careful check of the fuel gauge. This is the result. Note that I always brim the tank - and I do mean absolutely brim the tank - each time I buy fuel.

Odo Trip Distance       Fuel Gauge          Trip Distance          Predicted Range
Since Refuelling         No. of bars          Miles to Empty              Miles

      0                              12                       498                        498
     107                           11                       392                        499
     271                           10                       391                        662
     Not noted                   9                       
     343                            8                        320                        663
     376                            7                        288                        664
     414                            6                        253                        667
     456                            5                        214                        670
     Not noted                   4
     535                            3                        148                        683
     594                            2                          99                        693  Warning light came on at 78 miles
     652                            1                          54                        706 
     661                            1                          52                        713  Car refuelled with 57.7 litres of BP Diesel

The above table is not dead accurate - as I drove I took regular glances at the fuel gauge and noted the trip figures as soon as I noticed the number of bars change. Hence - if I didn't see the bars change at that instant - the trip distance would be slightly over-stated. But not by much - because I glanced at the instruments every minute or two.   

Make of this what you will.

The most significant thing for me is the sudden change in the predicted range (Trip Miles travelled since refill plus Trip miles to empty).  This test was done 3 fills ago - since then each time I refuel the predicted range to empty always starts at between 545 and 555 miles - it then very gradually increases as I travel but after around 200 miles it jumps to between 620 and 660.                               

[eye30]

So if I'm reading right

 the warning light came on during the 2 bars = approx 1.5 gallons
and 1 bar = approx 1 gallon

[AlanHo]

So if I'm reading right

 the warning light came on during the 2 bars = approx 1.5 gallons
and 1 bar = approx 1 gallon

I can't argue with that - but I would never trust the fuel gauge or Trip prediction to empty. When the low fuel light comes on - I head for a service station ASAP>

[Doggie 1]

Nothing less than expected from A.H. - a full diagnostic report on the issue raised. 
You really are wasted in retirement, Alan. 

[Phil №❶]

 

[neoto]

The most significant thing for me is the sudden change in the predicted range (Trip Miles travelled since refill plus Trip miles to empty).  This test was done 3 fills ago - since then each time I refuel the predicted range to empty always starts at between 545 and 555 miles - it then very gradually increases as I travel but after around 200 miles it jumps to between 620 and 660.                             

The same is in my 2011 i30. I also brim the tank every time. The predicted mileage stays at about 800-900 km UNTIL the (needle) fuel gauge moves from beyond full (or 1). From that moment on, the predicted mileage increases for the next 100-300 km, where it hits the somehow accurate value. I suspect that due to brimming the tank, the level sensor is overflowed and ECU therefore does not detect any change in fuel level and is in result unable to predict the mileage. As soon as the fuel goes below 100% full (in my case this happens after approx. 300 km or 15 L of fuel), the ECU starts with the prediction.

[Phil №❶]

@neoto,

That sounds like good logic to me. 

[IJM67]

 I have had the same query with my 12-plate I30 Tourer, so I e-mailed Hyundai and below is the reply I received hope this helps: -

Dear Mr Millhouse
 
Thank you for taking the time to contact Hyundai Customer Services.
 
I can confirm that your low fuel light with illuminate when the tank has 2 gallons / 10 litres left in the vehicle.
 
I hope this has helped answer your enquiry.
 
Yours sincerely
 
Charlotte Benton
Hyundai Customer Services


While waiting for the reply I had the fuel light come on, as I was driving I couldn't make a note of the mileage but I reckon I did a further 9 miles and then filled it up the following day after a further 8 miles and managed to get just over 49 litres into the tank.  So I think 10 litres seems a bit optimistic.

[eye30]

II can confirm that your low fuel light with illuminate when the tank has 2 gallons / 10 litres left in the vehicle.
 

Can you remember how many bars there were when the low fuel light come on?

Suppose the only way to know for sure is to actually let it run dry but make sure you have a can of fuel in your boot otherwise you may be left high and dry.....

[Doggie 1]

II can confirm that your low fuel light with illuminate when the tank has 2 gallons / 10 litres left in the vehicle.
 

Can you remember how many bars there were when the low fuel light come on?

Suppose the only way to know for sure is to actually let it run dry but make sure you have a can of fuel in your boot otherwise you may be left high and dry.....

There's a tavern there.

[The Gonz]

... otherwise you may be left high and dry.....

There's a tavern there.