Damn. You beat me to this one! Why didn’t I think of it earlier

 

Bruce I’m right there with you. Mine are a mix of Seinfeld, TNG, and early MASH. Of course when I use the Henry Blake or Radar references now I get blank stares from anyone under 40.

 

Good way to burn up the fuel pump on any car, with fuel pump in the tank .
The pump is cooled & lubed by the fuel in the tank.

 

A similar out of fuel experience in my XK showing between 1/8 and 1/4 tank: The models share a similar saddle-bag style fuel tank with an electric fuel pump in the right lobe and a jet pump in the left lobe. After confirming the function of both level senders using SDD, it was determined that output from the alternator is erratic. Periods of low voltage were not sufficient to trigger codes or warning lights. However, the low voltage is suspected of reducing electric fuel pump speed/pressure. Inadequate pressure to the jet pump leaves fuel stranded in the wrong side of the fuel tank. Residual fuel was confirmed on refilling the tank after the incident.
An accessory digital volt meter (cigar lighter) is recommended to monitor a possible low voltage condition.

best regards,
Bill

 

Another thing is the pumps are cooled by the fuel, running the car low on fuel will also cause premature wear.

 

Guess that people just don't realize they need fuel to cool & lube the pump.
No longer a twenty min job like the old American cars.

 

My car has no warning light at all. I was at 20 miles yesterday, no light, I filled up immediately.
The warning for this car is when it stops running completely, they should call it the "no warning, warning light" Be careful out there. I never had a car that did not light up on the dashboard when low on gas, even my 2016 S warned me. You can also add it than the gas gauge is way off all the time. Bad planning here.

 

My warning lamps come on at about 40 miles to empty, and I've had mine down to the 20 mile range without a problem. Fortunately, the fill never pushed total capacity. so I have some confidence on how the car is calibrated. But, I but agree you really don't want to push things too far, given the potential damage to the fuel pump. Technically, any damage could be considered outside the scope of your warranty. And, if you DO run out of gas, let the system prime before you just fill it and go. (Turn on Accessory mode without starting the engine and give it a few minutes.)

 

Yes my 2016 always lit up, I wonder why they changed it.

 

I don't think they did change it. The warning light comes on at less than 10% fuel remaining. Something was wrong on the OPs car that it thought it still had more than 10%, as shown by the fact that it thought it had 48 miles to go. Clearly something is off on the fuel sensor.

 

I will stop pushing mine to the limits. Pulled into station yesterday with 28 miles to go, but warning light came on with 34 or so miles to go. Have had it come on in both the previous R and now the SVR.

 

Take this seriously: repeatedly running low on fuel puts the fuel pump life at risk. This practice is the major cause of failed fuel pumps on modern cars. Once I learned that lesson (not on a Jaguar), verified by the dealer, I learned to fill up when the tank gets around 1/4 full.

 

In the UK I can't afford to fill a whole tank, so I never let it get too low!

 

The dealer is going to give me an estimate on replacing the fuel level sender, which is presumably the issue. Probably $$$.

 

A few weeks ago I wanted to burn up as much of the 4 month old gas that was in the tank of my 2021 F Type as possible and refill with some fresh gas. The warning light came on when it was around 40 miles until empty. I stopped at a nearby gas station and filled up until it was just about ready to overflow. The tank took just over 17 gallons. That seemed about right.

I suspect that the low fuel warning is a moving target; the computer calculates the miles until empty based upon the current average fuel consumption according to your trip computer. So maybe if you just put 300 miles on the car on the freeway averaging 27 MPG it would come on at a different point than if you were doing some spirited driving and your trip computer showed 16 MPG ? Pure speculation on my part as that was the first and only time I have run the tank down that low. I usually fill up when I still have more than 1/4 tank left.

 

The fuel tank takes the form of "saddle bags" which straddle the drive shaft and exhaust pipe.
There is a a pump and sender in each lobe or low point.
The pump on the right side is the electric "primary" pump which provides fuel to the high pressure pump on the engine.
The pump on the left hand side is a "jet" pump. The jet pump uses fuel under pressure (from the primary pump) to "pump" fuel from the left side lobe into the right side lobe.
Two problems can cause the jet pump to fail and strand fuel in the left lobe:
1) a block/trash in the orafice of the jet pump
2) low pressure from the primary pump

Since the "fuel level" indicated on the dash/gauge is the average of left and right sensors. it is quite possible to show an 1/8 of a tank or so when the right lobe is empty!
SDD "measurements" can show the individual sensors to help diagnose the fuel level/warning problem.

Low pressure from the primary pump may be due to a failing primary pump where pressure is sufficient to supply the secondary (high pressure) pump but not sufficient to power the jet pump, thus stranding fuel in the left lobe.
A chronic low/moderate voltage due to a failing alternator, etc may reduce primary pump pressure to a point that is insufficient for the jet pump to transfer fuel back to the right lobe, again causing the fuel imbalance.

The warning light feature appears to be based on the average fuel level rather than computed based on elapsed distance.
It would have been a better/fail-safe design if the lower of the sensors had been used to trigger the low fuel warning.

Please let us know what the dealer finds.
Best regards,
Bill

 

Fill mine up, before parking it for the winter, with the battery tender connected.