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Discussion Starter · #1 · (Edited)
OK, I now have some data for the 1 bar through 8 bar levels. These are limited to my car, and since I don't have that many results, a station with a auto-shutoff set differently than others could throw some numbers. That being said, I would love to hear any contradictory or matching data:

Reading--Expected--Measured/volume--Measured/%

8 Bars = 100% (per Alfa) = 15.3 (gallons, U.S.) = N/A

7 Bars = 87.5% = 12.3 = 80%

6 Bars = 75% = 10.3 = 68%

5 Bars = 62.5% = 8.6 = 56%

4 Bars = 50% = 6.6 = 43%

3 Bars = 37.5% = 4.7 = 31%

2 Bars = 25% = 2.9 = 20%

Orange = 15% = 1.6 = 11%

1 Bar = 12.5% = 1.2 = 8%

0 Bar = 0% (?) = Not that daring = UNK


These numbers make some sense if you consider the shape and format of the Giulia fuel tank.



The tank is a wide/flat saddle design that uses two float type senders whose inputs are probably averaged. The larger wedge area at the top is likely not measured completely, as there is also the crossover space, resulting in the high volume of the first bar. After that, the second bar is a little above the other average, but the next 5 are all in a 1.7-2 per range. The final bar's observed smaller capacity is likely down to the tapering bottom of the saddle-bags.
 

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That seems pretty consistent with what I have seen also. I personally try not to see under 3 bars. It seems to run through that portion very quickly.
 
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Brilliant work mate. Well done!
 

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Yes well done. My 360 has a bar graph gauge but the gas symbol light comes up at about 33% and not a 25% or less. In fact the gauge has 9 bars so you pretty much have to think in thirds but this is not very accurate. I've only had the gas light come on once since the first time.
 

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Thanks for doing the work to gather this info and share it here. It definitely seems to be a car where the orange wanring light really does mean start working out where to fill up.
 

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The manual says when the warning light comes on, you have 2.38 gallons of fuel left, and they say to start looking for a gas station. They specifically warn against running the car down below that, as it could damage the catalytic convertor. Basically, gas up when you get to 1/4 tank.
 

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The numbers the OP shows indicates half a tank (4 bars) according to the gauge, is 6.6 gallons. That means a "full" tank at 8 bars is 13.2 gallons out of a 15.3 gallon tank. This shows that the 2.1 gallon 'reserve' is all at the top. The best way to think about it, is to consider that in essence once you hit the warning light, you're actually down into the reserve.

The way they've chosen to calibrate the gas gauge, it's actually offset upwards by the amount of the reserve. The 1/4 tank mark isn't actually a 1/4 tank; you're half a gallon above the reserve. I'm not sure if there was a particular reason why they chose to calibrate it that way, but personally I'd prefer to have them shift the calibration down by the reserve amount, so the 2 gallon reserve is still there once you hit what the gauge says is 'empty'. That would make it less likely to damage the catalytic convertor or any part of the fuel system.

Unless and until they recalibrate what the gas gauge shows, everybody should start looking for a gas station at the 1/4 tank mark, because you've already used just over 12 of your 15.3 gallons.
 

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Discussion Starter · #8 · (Edited)
Nope, the warning light (orange gas pump vice white) is consistent at 1.6 gallons to empty. So about 8-12 miles later, the red single bar appears and we're 1.2 gallons from dry. The warning light ain't worth warm spit. Given Alfa suggests a 2.38 gallon reserve, we'd expect about 48-73 miles on "reserve"...where we seem to be getting 32-49 miles from the orange light...or about 67% of the promised reserve.

Also, given that 8.6 gallons are in the first half of a tank and only 6.6 in the last half, the "estimated range" is insanely optimistic. I've seen my range fall from 115 to 67 miles in a 15 mile drive.

Since the Alfa is so electronic, perhaps they could recalibrate the fuel levels with an RRT?
 

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Discussion Starter · #9 ·
OK, now have a little more data, and the earlier findings are staying pretty much the same. The 5 bars and 3 bar amounts dropped slightly and the 2 bar level climbed a smige.

The top bar is pretty much 3 gallons. After that, the numbers don't make much sense (not that 3 gallons vs an expected 1.91-2.0), going 2.0/1.5/2.2/1.7/2.0/1.7. Until I have a few more fills at each level, some of these numbers could jump a bit, but a few things are obvious:

2 bars = gas me now = true...= about 2.8 gallons left vs expected 3.8.
Orange gas pump = Reserve = false...= about 1.6 gallons left vs expected 2.3.
1 red bar = getting low = false...= oh ****, about 1.2 gallons left vs expected 1.9.

If anyone has seen ZERO gas bars, please report what happened.
 

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Discussion Starter · #10 ·
The manual says when the warning light comes on, you have 2.38 gallons of fuel left, and they say to start looking for a gas station. They specifically warn against running the car down below that, as it could damage the catalytic convertor. Basically, gas up when you get to 1/4 tank.
BTW, the manual I have says 2.3 gallons (9 liters)...but 9 liters is 2.38 U.S. gallons, not 2.8, as that says.
 

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Discussion Starter · #11 ·
With some new data, the points have moved a little, but here's something to look at and consider. The following chart attempts to predict indictated fuel level vs miles travelled. Anyone that uses this and finds it failing, please give me your data.
 

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One item that has gotten my attention on the Alfa vs. my BMW 335i or my Acura for that matter:

I've seen the gas gauge go to the last bar (still getting used to her thirst), and the Miles Til Empty number on the bottom right of the center digital read-out goes to "---"

That's fairly disconcerting for me, as I've been hopping along with 30+ miles to go, then I look down, and I get ---. I translate that as "lace your shoes and put your coat on, you're pushing any time now".

Not sure if others have seen that, but it's going to take getting used to, as my other two cars can get it down to the minute mile or two with 100% accuracy down to the bottom of the gauge.
 
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Discussion Starter · #14 ·
I assume:

Distance since refill/(MPG-1.5)=Fill

I then assume:

Fill>14.5=Pushing shortly

I don't like to see the Orange gas pump, so I'm only seeing it in town when I KNOW where to gas up when it turns RED for my testing.
 

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I refueled for the very first time Friday. Quite concerned when the miles-to-empty went straight to "---". Based on how much further I drove and how much gas the car took, I estimate I still had about 2 gallons left when that happened.

The car took 14.1 gallons (w/o topping off). When I turned it off to refuel, it was showing 2 red lights. Based on the data in this thread, it probably was within seconds of dropping to 1.
 

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Discussion Starter · #17 ·
Awesome work! Thanks for sharing AlfaCrisis!
Thanks, the good news I see that I have multiple fill ups at all but zero now. I’m chasing a few more fill ups (5, 4 and 3 bars) before I look to fine tune the numbers. I have standard deviations on all the bar levels, and will focus on a few more fill ups on those that are significantly higher than the rest. Hopefully then I will have some new and solid data to put out and have people compare with.
 

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I refueled for the very first time Friday. Quite concerned when the miles-to-empty went straight to "---". Based on how much further I drove and how much gas the car took, I estimate I still had about 2 gallons left when that happened.

The car took 14.1 gallons (w/o topping off). When I turned it off to refuel, it was showing 2 red lights. Based on the data in this thread, it probably was within seconds of dropping to 1.
I was searching for this weird behavior that I'm seeing in my car and found this thread. It seems like a bug that the "vehicle range" or miles-to-empty shows "---" as soon as the reserve light comes on. That's just when this information is the most valuable to the driver! Has anyone reported this to the dealer service as an issue? Like other have said, most cars like Audi and BMW do not do this.

Edit: After more searching I found another thread that is discussing this http://www.giuliaforums.com/forum/289-alfa-romeo-giulia-general-discussion/11913-empty-gas-tank.html. Macgeek says it's normal, so who am I to disagree ;)
 
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When I was at zero bars I got about 10 miles of range before I ran out of gas. My best estimate based on the fact that I was in A mode but in heavy traffic is that zero bars means you have around 0.5 gallons of fuel or less.
 
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I was driving home from work yesterday which is about 25 miles. I left work with no warning lights and about 1/4 tank. Shortly after I left it went to yellow, and then a few minutes later RED!!! I sweated it out to my exit and got gas at the end of the ramp. I filled it up and put 14.6 gallons in. Never again.
 
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