Whats with the low fuel light?

[MEC-777]

On the first tank, I filled up the moment the low fuel light came on, only to discover it only took 39L to fill. Having a 48L tank, isn't that a little too early for the light to come on?

That means I still had 9L or so and could have traveled another 100kms easy. I guess they just want to give people lots of warning.

In both my previous vehicles, when the low fuel light came on, you had maybe 5L of fuel remaining or less.

I'm really loving this car, just thought it was odd the light comes on so early. Is it the same for the rest of you?

[dmlexpert]

That seems normal to me. When you get to the last pip on the gage, the low fuel light comes on. After that, the pip starts blinking and that means it needs to be filled right away to protect the fuel pump and avoid possible catalyst damage (and check engine light with P030x code(s) too) from misfiring due to fuel starvation. My car also takes about 10.something gallons (38-39 liters) to fill when the low fuel light comes on.

[MEC-777]

Originally Posted by dmlexpert

That seems normal to me. When you get to the last pip on the gage, the low fuel light comes on. After that, the pip starts blinking and that means it needs to be filled right away to protect the fuel pump and avoid possible catalyst damage (and check engine light with P030x code(s) too) from misfiring due to fuel starvation. My car also takes about 10.something gallons (38-39 liters) to fill when the low fuel light comes on.

Ah, ok. Good to know.

About how long after the light comes on will the last bar start to blink?

9L is still a decent amount of fuel for regular driving. I used to run my civic down to fumes (seriously, it would stall out in corners and heavy braking, that's when I knew it was really time to get to the pumps), not that I would do that with this car, but just trying to get an idea of how far this car can safely go after the light.

Thanks.

[dmlexpert]

The distance from one pip to blinking pip seems to be about half the distance of what it takes to get from the second pip to first pip. That varies from car to car, driver to driver, city to city, depending on the fuel economy realized by each unique combination, number of cold starts, and so on.

I usually fill up as soon as I lose the second pip - if not sooner - because I don't see a purpose in pushing the limit. But if your commute involves long distances between filling stations, and you lose the second pip, you do have time and distance on that first pip before you're in the danger zone.

[MEC-777]

That makes sense. Yeah, I don't purposely push to the last drop often, but I like to know how much further I could go if need be.

[lovemysantafe]

A few on here have reported running out within 10-12 miles (16-19 km) of the last bar starting to blink. Remember that very rarely is the tank filled to its rated capacity so you're often dealing with less than the capacity of 12.8 US gallons (48.5 liters).

If I pull in right at the low fuel light, it usually takes about 10.3 gallons.

[N5S-Matter]

I never run that low, just so I'm not risking sucking in moisture riding the top of the fuel. Soon as the light comes on, I hit the pumps.

[someguy]

I usually fill up with 3 bars remaining and put between 9-10 gallons in the tank. The few times the light has come on I put between 11-12 gallons.

[lovemysantafe]

Originally Posted by someguy

I usually fill up with 3 bars remaining and put between 9-10 gallons in the tank. The few times the light has come on I put between 11-12 gallons.

Are you topping off or hanging it up once it shuts off the first time? I've never been able to get more than 11 gallons in my car on the blinking bar.

[RXElantra]

I never run that low, just so I'm not risking sucking in moisture riding the top of the fuel.

Water is heavier than gasoline. Any water will sit at the bottom of the tank. E10 fuel is different in that any moisture is absorbed by the alcohol - until you get too much water, then phase separation occurs. Then the ethanol and water solution will separate from the gasoline and settle at the bottom of the tank.