Fuel gauge inaccuracy?

[996GT2]

The summary basically states it all. In the manual for my Honda Accord, it says that the fuel tank can hold around 17 gallons. However, the gauge always reaches the "E" line after about 13.5 gallons have been used and the emergency red light comes on when around 14 gallons of fuel have been used. This is from the counter at several gas stations, which read 14.2 gallons for the fill-up when I refilled after the red light came on. Why does the emergency light come on so soon and are there really still 3 gallons left in the tank when it does come on?

 

[ElFenix]

if the fuel pump is in the tank and uses gas as it's coolant it may come on 'early' so you'll fill up before the pump's coolant (gas) drains.

otherwise, i'd say it's for stupid americans who forget to fill up.

 

[programmer]

The owner's manual in my van states that the fuel light should come on with 2.1 gallons remaining in the tank. In reality, its more like when there is still 3.5 gallons left.

In general I agree they make these "warning" lights come on too early but there have been a couple of times where I've been driving on a stretch of interstate without a gas station for 50+ miles and I've gotten worried if I would make it to refuel. Always made it. 🙂

 

[spidey07]

That's why it's called the idiot light. To keep people from running out of gas.

 

[nakedfrog]

They've been doing that since what, some time in the 80s? I know that E meant E in my 78 Wagoneer.

 

[jagec]

Makes sure you don't run the car dry and blow your fuel pump
Makes sure you'll make it to the next gas station, even if it's a ways away
Also, just because the tank is a given size doesn't mean that the pump can get all of it.
Finally, the transfer functions they use to map the level sensor to the fuel gauge just plain suck. It seems that they always stay stuck on "F" forever, and then swan dive to 1/4, stay there for a while, and then plummet to "E" and turn on the light when you've got a few gallons left.

 

[Pacfanweb]

Originally posted by: spidey07
That's why it's called the idiot light. To keep IDIOTS from running out of gas.

Fixed that for the new, kindler, gentler Spidey.


It's called reserve. You don't want the low fuel light to come on and you run out of gas 3 minutes later.

You should really never let your car get much below 1/4. Gas gauges have never been, and never were intended to be super accurate. Plus, you never know when your sender will decide to go bad and start reading wrong.

So when you hit 1/4 tank, fill it up.

 

[LTC8K6]

Did you want it to come on just as the engine starved for fuel?

 

[Capt Caveman]

Mine comes on and I know I have about 50 miles left.

 

[thomsbrain]

That's just when the light comes on in these models. Yes, you still have 3-4 gallons left in the tank. It's been like that in every generation of Accord since 1990 (and maybe earlier, but I haven't driven any older than that).

 

[M2008S]

lol youve got the its better safe than sorry fuel gauge, see my chevy truck (redneck rigged out the ass) used to run out when the gauge was all the way down, not it runs out at approx 1/8 tank

 

[getbush]

I don't understand. You'd rather the light comes on and then 1 minute later the engine cuts out?