Fuel Warning Light - How many Gallons remain when comes on?

If I remember correctly, years ago when vehicles started coming with low fuel lights, it was calculated that the average distance in rural areas between stations was about 54 miles. Manufacturers based the low fuel light on how many gallons it took to go 54 miles. A fuel efficient car might only have 2 gallons left where a different one might have 5 gallons left. The computerized fuel monitoring has likely changed this, but my 2015 Cummins 2500 has about 5-6 gallons left when the light comes on regardless of towing or not.

OMG if it says Hey I need fuel, then just do it.
Why would you bother discussing the amount of fuel left and why or why not you would tempt fate or potential parts failures, replacements and whatever else was fubarred ?
I like to drive not wait for CAA (AAA) to find me in the middle of the night.
My family has 3 gas vehicle 2004 Dakota, 2008 Ranger and i have a 2023 Durango RT.
The rest are diesels. You don't fuel around with diesel.
Just do it.
If I sound like your wife, I am one.

Different Drummer said:

Mine will take 26 gallons when the fuel warning light comes on. I have a 32 gallon tank. I have a couple of times run the truck for 100 miles after the fuel warning light illuminates and have never managed to pump 30 gallons into the tank.

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Same here

Tominator223 said:

Also running fi vehicles low all the time will shorten the life of the fuel pump.

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As discussed earlier, this is no longer correct and hasn't been in years, possibly decades. The pump is 100% of the time submerged in fuel that is constantly being replenished. The only way to effectively shorten the life of the pump is to run it so low that it can't physically pick up fuel from the tank anymore, and allowing the canister the pump sits in to run out.

ReddJackson said:

I wouldn’t know, because of the price of diesel I never let it get below half empty

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What difference does it make if you're putting in 15 gallons twice or 30 gallons once? That makes no sense at all.

When diesel is over $5.00 per/gal…for me it matters

Gr8bawana said:

What difference does it make if you're putting in 15 gallons twice or 30 gallons once? That makes no sense at all.

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It's about risk. I can put in 15 gallons now for 3.45/gallon, or take the risk that the price won't go up when I need 30 gallons. Granted the difference is likely only going to be a few dollars, but we've all been conditioned for years that the price of fuel moving .10-.20/gallon is the end of the world.

FWIW, even if the price moved a full dollar between this week and last week, the difference over that 30 gallons is only $30. I spend that on stuff I don't need every week anyway.

2003F350 said:

It's about risk. I can put in 15 gallons now for 3.45/gallon, or take the risk that the price won't go up when I need 30 gallons. Granted the difference is likely only going to be a few dollars, but we've all been conditioned for years that the price of fuel moving .10-.20/gallon is the end of the world.

FWIW, even if the price moved a full dollar between this week and last week, the difference over that 30 gallons is only $30. I spend that on stuff I don't need every week anyway.

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Some of us are retired with a fixed pension.

The thought of donating any more $ than absolutely necessary to the petroleum companies or gov't thieves is not appreciated or tolerated.

YMMV

.

Y'all are off.

First, the low fuel light comes on when there's approximately 50 miles left.
Second that varies from truck to truck driver to driver based on average mpg. If you drive your truck hard and drive it like you stole it and your MPG is averaging 8 miles per gallon then when your fuel light comes on you're going to be at just over 6 gallons in your tank. For a minimum of 50 miles. So if you drive it super easy at that point you will get more than 50 mi out of it.

With that said if you drive it easy and get an average of 25 MPG, when your low fuel light comes on you should be down to 2 gallons of gas. And if you start to drive it hard where your average goes to 10 MPG, then you'll run out of gas before the 50 miles.

The amount of fuel remaining in the tank varies on your average mpg at the time it reaches 50 MI left. All due to driver driving habits. It's all calculated by the computer based on average mpg.

ReddJackson said:

When diesel is over $5.00 per/gal…for me it matters

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Haaa. Well you are still burning the same amount of fuel and spending the same amount of money…just driving less between fillups and not having such a large fillup bill.

olyelr said:

Haaa. Well you are still burning the same amount of fuel and spending the same amount of money…just driving less between fillups and not having such a large fillup bill.

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Yes, but by always being half full he can wait for the price to drop mid week or till he gets to a station with lower prices. Especially when travelling, timing your fuel stops using gas buddy can save significant dollars. When the empty light is blinking, you pay whatever the price is within your 50 mile to empty window.

Some think 20 or 30 bucks more or less, is no big deal, for others it is. I know when I look at my Visa bill there are few charges over 100 buck, most are 15 to 35, but it still adds up to 4 or 5 thousand every month. Strcitly your choice, but for some the money they save on gas prices is a big deal.

I dont see why when someone puts gas in the tank its an issue for anyone to reply to this.....what business is it of yours whether someone fills at 1/2 tank 1/4 tank or even fumes left?.....
People can fill whenever they want I wouldn't say a word,not my business and really dont care.ive helped others out at the pump with a few gallons here and there..I get it,been on that side before.
When I was a kid we didn't know what a full tank of gas was. Same applies today to people as another has said fixed incomes or whatever their situation....their business.
"I have just enough money to get a couple gallons til Friday until I get paid"(single mother and have enough for food on the table for the kids,that was my scenario as a kid)...today I get gas when I want, where I want and however amount i want....I've run the dam thing just about slap empty just to see what would happen with a full five gallon can in the back to see about the light,about miles to empty and to see how many miles I could drive after it said zero miles.....so I would know what my vehicle can do if needed.

From my experience on my 2500 with 31 gal tank i would say its about 5 or so gal left over when the light turns on.. This is based on putting 26 gals in the tank at fill up when the light turns on.

When i was in High School, i hit my Dad up for Movie or Bowling money.
I knew that i had to leave enough gas in the car, for the next driver to make it to the Sunoco station, which was about 8 miles away.

Now, i have to hold onto enough cash to get where ever i have to go.
No, i don't use a Debit or Credit card, the California stations charge ten cents a gallon, if you use a card.
Some stations charge 20 cents per gallon

Gr8bawana said:

Has anyone ever read in their owners manual to never let the fuel get down below a certain level because the fuel pump will be damaged? No.
It just doesn't happen.
I don't know how this myth got started to begin with. Maybe if an electric fuel pump ran for a long time pumping nothing it might be damaged.

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Back in the seventies, I believe, a certain manufacturer (not Chrysler) used a fuel return system that essentially allowed the fuel pump to run all the time. These suffered a lot of failures and the civilian theory was the pump was overheating.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, 18” wheels. Build Date: 3 June 2018. Now at 113515 miles.

Zoe Saldana said:

I need to know how many gallons are in the tank when the Fuel Warning Light comes on. I usually, don't go that low.

My 2500 has a 31 gallon tank and I vaguely remember in the past when the light went on I was able to put in 25+ gallons which would mean about 6 gallons or a bit more (because I took some time to get to the gas station).


What are your thoughts?

Thanks

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My 1500 has the 32 gallon tank. The light comes on at about the 26 gallon mark.

I'll have to come back and edit to add the link, but I've been down this road and posted about it.
32 gallon tank like others have posted the light would come on and it would take 26 gallons.
So what I did was using ALFAOBD I recalibrated the BCM. From the factory it had the tank capacity as a 26 gallon tank (actually they had it in liters). So I switched it to the larger 122 liters.
Now every 1/4 increments are 8 gallons of fuel. Why is that important? I travel and have fuel accounts that can save me ALOT of money plus I have a 92 gallon in bed tool/fuel box. So knowing my gauge is accurate at every 1/4 increments, I know how much fuel I'm using out of my reserve when I top off. Plus I can keep track of how many miles I can go to get to that next big discount fuel station to fill everything back up again.
The math:
$3.85 reg price x 100 gallon = $385
$3.15 discount price x 100 g = $315
Savings $70. Every trip that's atleast a two time occurrence equaling $140+
It all adds up. This is why I needed the accuracy. This also proves the effectiveness of having a reserve in bed tank.
The maps below show the current price differences and how it varies alot between my discounted stations and local.

ReddJackson said:

I wouldn’t know, because of the price of diesel I never let it get below half empty

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How does the price of diesel relate to the fuel tank level?

Zoe Saldana said:

How does the price of diesel relate to the fuel tank level?

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It's mostly psychological, we as a society are conditioned to see fuel prices go up 20-30 cents and think 'man that's expensive!' When the reality is, for MOST people on the average of 20 gallons, it's not that much money - $4-6. Even a 50 cent jump is only $10 per tank. But filling up at half a tank is less psychologically draining/alarming than filling up from empty. It also allows you to 'feel good' if fuel prices move up after you fill up - you got a 'deal.'

Yes, there's people who prices moving affects drastically, but most of those people don't usually fill up every time anyway, they're putting $10-20 in at a time to get by.

Sounds like you used the most accurate method. I have run my 2020 with 26 gallon tank till warning comes on a few times. I usually takes 22.5 to 23 gallons. This leaves 3 to 3.5 gallons. I try not to run it down that far, also my aged bladder usually makes me stop. Once had a Chevy PU company car that when it said 40 miles left the truck stopped.