Low fuel warning light: 2001 F-150

I checked my owner's manual (don't tell anyone) and it only says the warning light signifies low fuel.

How many gallons are left in my tank when the low fuel warning light comes on?

2001 F-150 Supercrew
Reply to
Bryan
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Makes sense. If your low fuel warning light comes on, you're low on fuel.

Probably 3-5 gallons. Time to fill up. Your owner's manual should also have the tank capacity listed. When you fill up, note how many gallons it takes, then subtract that from the capacity and voila! you know how many gallons you have when the light comes on.

Fuel gauge senders are typically designed to be only approximately accurate. My '02 F250 comes on when I have about 2 gallons left. My wife's '04 Wrangler Unlimited comes on when it has 7 gallons left. Wish it was the other way around.

Reply to
Matt Macchiarolo

I don't know for certain, but the vehicles that I have owned with this light seem to carry about 3 ~ 4 gallons when the light comes on.

You can figure this out though.

Fill the tank and notate the mileage. The next time you need gas, FILL the tank again and notate the mileage again. Subtract the bigninning number from the ending number, and divide that by the number of gallons you buy. The result is your average mileage for the type of driving you do.

Repeat this a few times to get an average over a longer term. (Add all of the fuel mileage numbers together and divide by the number if figures you added together, ie. 15.9 +14.6 + 16.6 = 47.1 / 3 = 15.7)

Now, you will have found that you can get about 15.7 mpg, and you already know the truck has a <nn> gallon tank (let's just say 25 gallons). This says you should be able to go about 390 miles on a tank, if the light comes on at

345 miles, then you still have about 3 gallons (15 x 3 = 45 + 345 = 390) in the tank when the light comes on.

You need to do the math, but simply substitute your actual numbers for my pretend numbers and you should come up with something in the range of 4 gallons remaining when the light comes on.

Reply to
Jeff Strickland

I was afraid there wasn't a more accurate setting. When I'm hauling my trailer at 7mpg I'd really like to know if I have 2 gallons left or 5. Of course, when I'm hauling my trailer I try to practice the half full is empty policy.

Reply to
Bryan

As you've both suggested, the sender's are only approximately accurate. That makes my low fuel warning plus full tank difference only approximately useful.

Reply to
Bryan

I'll have to brave it out and wait until the light stays on. I've always filled up when the warning light can't decide whether to stay on or off.

Reply to
Bryan

NO!

You do not have to brave out anything. Fill the tank three or four times IN A ROW, and caluclate the MPG, then multily your MPG by the total fuel load that you can carry. This will tell you the total range. Using your Trip Meter, you will find that the Low Fuel indicator comes on with roughly 3 to

5 gallons remaining. There is nothing to "tough out" because since you do not know the unknown, you can caluclate the unknown based on knowns.

You know the MPG (or can find it easily). And you know the total capacity of the tank. With these two known conditions, you can figure out when the Low Fuel light will be coming on, and how far you can go before you have to start walking ...

Reply to
Jeff Strickland

I know what you're saying, but it doesn't satisfy my curiosity about the warning light setting and the sensor's accuracy. Besides, my mileage varies. Sometimes I'm driving around town. Sometimes on the freeway. Sometimes I'm towing a small boat. Sometimes I'm towing a 25 ft trailer.

I do understand your suggestion. And thanks.

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Reply to
Bryan

That's why you keep track over several tanks of gas. The light will come on with the same amount of fuel remaining, the difference in how you drive will only alter the miles when the light comes on.

If you are humming along on the freeway and the light comes on, you have 4 gallons at 20 mpg, but if you are dragging your boat across the landscape and the light comes on, you have 4 gallons at 15 mpg.

It's a good rule of thumb to get gas as soon as is practical after the light comes on.

Reply to
Jeff Strickland

I read, saw, heard, or it came to me in a dream that the auto manufacturers generally based passenger car fuel tank size on being able to go 300 miles on a tank of gas (using avg. MPG for the vehicle), with the low fuel light coming on when 50 miles of gas remained. (1) is that true? and (2) does that rule apply to trucks, albeit maybe 500 miles per tank full?

Reply to
Agave

My dad had a Volkswagen when I was a kid. When it got to empty there was a lever on the floor that you kicked over to access the reserve tank. Just enough gas to get to the next gas station. At least that's the way I remember things.

Reply to
Bryan

According to my Expedition's Miles to Empty Function, my Expedition with a 28 gallon tank will go about 435 miles on a tankful. The low fuel warning comes on when I have 50 miles to go. This figures out to around 3 gallons.

Ed

Reply to
Ed White

Except for my 95 Bronco, all of my cars would go closer to 400 miles on a tank of gas, and the light came on with about 75 ~ 90 miles remaining.

It seems by the math that my Bronco follows the rule too. I can carry 32 gallons, and get from 11 to 15, depending on what kind of driving I'm doing. If I can muster 12.5 mpg, then I can go 400 miles on a tank.

Reply to
Jeff Strickland

On my 01 Excursion, the low fuel light comes on when the digital display up top says I have 12 miles to go till empty. I had taken a 5 gallon fuel can with me on my test.

I watched the number drop to 0 and then set my trip and went another 57 miles till she sputtered.

After changing my fuel filter, to be safe, and adding three bottles of gummout, also to be safe with a 44 gallon tank all is well and I know that when the light comes on I have approx 65-70 miles to go till dead.

Reply to
Rob R.

Thanks Rob. Taking into account all the replies, my low fuel light is nothing more than a get gas now light. Ok, I can live with that.

Reply to
Bryan

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