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Why wait? It takes time and I don't like wasting time. I also drive in areas where gas stations are few and far between so I often need to ask "can I make it to the next station or do I need to buy $5/gallon gas in Bridgeport, Ca?"

To each his own -- it takes less "wasted time" to fill up less fuel than waiting to fill a complete tank.

Giulia does not have fuel float(s). She has electronic sensors.

I thought that might be true -- and is why my original statement noted: "This is because at full, the fuel level in the tank is "higher" than the actual highest limit of the fuel level float, or whatever sensing device is used to send data to the gauge"

I made some measurements of the fuel sensor output while I added 1/2 gallon at a time to the car and got very confusing results. I'll process the measurements later but one thing that was really obvious is that the output has a considerable amount of hysteresis as I had to add quite a bit of gas before the reading changed at all. I presume the hysteresis is there to mask apparent fuel level changes when the car is on a slope or accelerating.

I have found a similar "buffering" of my oil gauge in my BMW -- if I add 1/2 quart, when low, it will not be immediately reflected on the electronic level gauge.
 

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I would agree with the recent comments (e.g. gauge non-linear, no drop in fuel after first gallon burned). Also I have found, for another data point, that I can put an extra 1.3 gallons in after the pump auto-shuts off. It requires multiple, multiple squeezes to do. Yes, I know some people have said this can cause some sort of damage in the evaporation system but I have not seen it). This is however, a lot of extra gas in my experience.... another Giulia oddity. When I do this I do get extra range but the computer is indifferent about calculating. Sometimes I get the usual 327 miles. Sometimes I get 350 or so. I've even gotten 410 on the read-out. When done, the gauge doesn't drop for maybe two gallons so I'm definitely above the standard run of the sensor....
 

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Tipo 33 Stradale 1/18 scale
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the fuel gauge is a rough guide only - there is a very simple calculation is do that tells me how many litres of fuel i have used - and it is very accurate at the pump


distance travelled = 427.6 kilometres


fuel consumption 10.7 litres/100 klms


simply multiply 10.7 x 427.6 = 4575.32 divide by 100 and that gives you 45.7532 litres used - if the pump is accurate you will get 46 litres into the tank



from that you know you have 9 or so litres left in the tank


dont know how any of that converts to American or UK gallons, but the principle is the same
 

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Why wait? It takes time and I don't like wasting time. I also drive in areas where gas stations are few and far between so I often need to ask "can I make it to the next station or do I need to buy $5/gallon gas in Bridgeport, Ca?"

Giulia does not have fuel float(s). She has electronic sensors.
Giulia also has a complex shape fuel tank and evidence has it that there is no compensation for the shape of the tank.

I made some measurements of the fuel sensor output while I added 1/2 gallon at a time to the car and got very confusing results. I'll process the measurements later but one thing that was really obvious is that the output has a considerable amount of hysteresis as I had to add quite a bit of gas before the reading changed at all. I presume the hysteresis is there to mask apparent fuel level changes when the car is on a slope or accelerating.
try my formula lockie, see how you go ... it requires resetting the trip meter when you fill up


make sure you report back ... with a pressie, like an Alfa Romeo Formula One jacket :)
 

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I would agree with the recent comments (e.g. gauge non-linear, no drop in fuel after first gallon burned). Also I have found, for another data point, that I can put an extra 1.3 gallons in after the pump auto-shuts off. It requires multiple, multiple squeezes to do. Yes, I know some people have said this can cause some sort of damage in the evaporation system but I have not seen it). This is however, a lot of extra gas in my experience.... another Giulia oddity. When I do this I do get extra range but the computer is indifferent about calculating. Sometimes I get the usual 327 miles. Sometimes I get 350 or so. I've even gotten 410 on the read-out. When done, the gauge doesn't drop for maybe two gallons so I'm definitely above the standard run of the sensor....
327? :surprise: that's what mine always says. Cannot be a coincidence
 

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Same here 327.......
Mine always says 400 after a fillup. very occasionally i've had 500+ mile readouts but those quickly "corrected" themselves >:)
 

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Being in the USA distance is miles and fuel economy is miles per gallon. To compute fuel use one needs to compute

miles/MPG

I've bothered to measure and most of the time that I spend getting gas involves exiting the highway, re-entering the highway and fiddling with a credit card; not the actual fueling.

I can at most add 0.2 gallons after the first fuel filler shut off.

Hysteresis is not the same as a time delay. Time delay and time averaging are also not the same. I assume that time delay is pointless so not present and time averaging would be sub-second. Maybe a wrong assumption?

Here are the measurements I made. The first column is the fuel reading, the second column is fuel added in USA gallons according to the pump, the third column is the change in percentage reading for 0.5 gallons added.

35.7 0
35.7 0.5 0
35.7 1.0 0
35.7 1.5 0
49.8 2.0 14.1 (3.5% per half gallon)
49.8 2.5 0
49.8 3.0 0
51.0 3.5 1.2 (0.4% per half gallon)
54.9 4.0 3.9
60.0 4.5 5.1
63.9 5.0 3.9
66.7 5.5 2.8
71.0 6.0 4.3
73.7 6.5 2.7
76.9 7.0 3.2
80.8 7.5 3.9
84.7 8.0 3.9
87.8 8.5 3.1
91.8 9.0 4.0
95.7 9.5 3.9
98.8 10.0 3.1
100.0 10.2
100.0 11.3 (full)

The average ranges from 3.1 to 3.5 % per half gallon added depending on what points are taken for the averaging. Assuming I had 4 gallons remaining in my tank the remainder of the tank would have to average 4.3% per half gallon. In spite of the strange behavior when I added the first 3.5 gallons this simply confirms the other measurements folks have made: the gauge drops faster at the bottom end of its range. Unfortunately using the reported fuel fill percentage does not help much with this behavior. The one thing you do get with looking at the percentage fill is avoiding the "ceil()" operation on the fuel bars on the instrument panel, which exaggerates the whole "how much fuel do I have left" issue.
 

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Mine always says 400 after a fillup. very occasionally i've had 500+ mile readouts but those quickly "corrected" themselves >:)
DTE depends on the fuel economy that you have been getting for the last 10-20 miles before your fill up. I have had it read as high as 780 miles after a fill up after a downhill run.
 

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Just to add a bit to this thread, I filled up this weekend when my gauge indicated exactly half full, and the pump shut off right at 10.002 gallons. Since premium was 2.999 or whatever that cost was exactly 30.00. I didn't try to top it off after that. OCD members will appreciate this picture:

 

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OK, this is screwy. I always fill an extra 1.3 gal after pump auto-shut off. Given this habit yesterday I was down one bar and decided to refill after driving 58 miles - which on city driving of 20 mpg should be over 2 gal down. I put in about 2.5 gal also by squeezing off the extra 1 or 1.3 gal as usual and when restarting the guage still showed I was down 1 bar and only had a range of 269 instead of 327 miles as usual. Even if the guage registers at the auto-shut off which should have been apparent after draining 2 or 2.5 gal with my usual overfill I should have raised the indicated level. In other words, driving 58 miles and refilling the same as usual should have risen the guage. The fact it didn't shows some software buffer or something which is clearly impairing an accurate evaluation of level in this car....arghh.

Sent from my HTC6545LVW using Tapatalk
 

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I've had my QV for two weeks and I'm actually having a hard time feeling comfortable with how much fuel I have left. With my old car, I knew the gas light came on with 3 gallons left and the range read 0 with 2 gallons left, which gave me exact mileage until I was desperate for fuel.

I've filled up immediately (within 2 miles) upon the gauge lighting up to try and figure it out and I got vastly different amounts to full (always first click, I never top off).

1st time: 13.3 gallons
2nd time: 12.5 gallons
3rd time: 14.3 gallons

That lack of consistency makes it so I feel obligated to fill up the instant I see the gauge light.
 

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I've had my QV for two weeks and I'm actually having a hard time feeling comfortable with how much fuel I have left. With my old car, I knew the gas light came on with 3 gallons left and the range read 0 with 2 gallons left, which gave me exact mileage until I was desperate for fuel.

I've filled up immediately (within 2 miles) upon the gauge lighting up to try and figure it out and I got vastly different amounts to full (always first click, I never top off).

1st time: 13.3 gallons
2nd time: 12.5 gallons
3rd time: 14.3 gallons

That lack of consistency makes it so I feel obligated to fill up the instant I see the gauge light.
After a while you'll learn the range and know when you need to fill up. For me, I fill up about every 200 sMiles
 

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OK, this is screwy. I always fill an extra 1.3 gal after pump auto-shut off. Given this habit yesterday I was down one bar and decided to refill after driving 58 miles - which on city driving of 20 mpg should be over 2 gal down. I put in about 2.5 gal also by squeezing off the extra 1 or 1.3 gal as usual and when restarting the guage still showed I was down 1 bar and only had a range of 269 instead of 327 miles as usual. Even if the guage registers at the auto-shut off which should have been apparent after draining 2 or 2.5 gal with my usual overfill I should have raised the indicated level. In other words, driving 58 miles and refilling the same as usual should have risen the guage. The fact it didn't shows some software buffer or something which is clearly impairing an accurate evaluation of level in this car....arghh.

Sent from my HTC6545LVW using Tapatalk
I would not overfill, the evap system of this car is very sensitive. It also mentions it in the manual :wink2:
 

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Had this happen the other day. I have a 2020 Giulia Ti Sport and the low fuel light came on right around 11 gallons used (by the time I filled up it took 11.6 gallons to first click). Not knowing how big the tank was I looked it up thinking it would be 13 or so gallons and it was 15.3! By my estimates that's at least 4 gallons of "reserve" after the low fuel light comes on which is over 25% full! I can see why Alfa would want to give a buffer for people so they don't run out of gas, but from a philosophical standpoint if that warning is triggered so early, is it even an effective warning? Knowing I can drive almost 100 miles with the low gas light on might make me push the range... the exact thing Alfa is trying to avoid me doing:unsure:
 

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Had this happen the other day. I have a 2020 Giulia Ti Sport and the low fuel light came on right around 11 gallons used (by the time I filled up it took 11.6 gallons to first click). Not knowing how big the tank was I looked it up thinking it would be 13 or so gallons and it was 15.3! By my estimates that's at least 4 gallons of "reserve" after the low fuel light comes on which is over 25% full! I can see why Alfa would want to give a buffer for people so they don't run out of gas, but from a philosophical standpoint if that warning is triggered so early, is it even an effective warning? Knowing I can drive almost 100 miles with the low gas light on might make me push the range... the exact thing Alfa is trying to avoid me doing:unsure:
Warning is supposed to come on with 2.38 left I believe
 

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Is it possible my gas station's pumps auto shutoff early? Read through three other similar threads and I'm just as confused as before
 

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At exactly 1/2 tank i can put 9 gallons of fuel in the car. I found that odd since we dont have 18 gallon tanks
 
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