Topic: incorrect fuel gauges

[haijing]

hey guys, I have a 95 Altima,  I know the car has a 60L tank, but when the fuel gauge shows empty and I go fill it up, I only register about 40L.  Does anyone know the exact problem?  is it pricey?

If I don't fix it, what are some of the strategies that I can use to prevent running out of gas?

Henry

[si]

that is normal.

you have excess fuel in reserve well beyond when the tank says E (usually) 

and the tank can also usually take a lot more gas than when the first few "clicks" automatically shut off the flow when re-fueling - although it's good not to fill up the car right to the brim.

[mmret]

Its normal that the gauge doesn't scale the full usable volume, but a "missing" 1/3 seems like a lot.

[ovr50]

hey guys, I have a 95 Altima,  I know the car has a 60L tank, but when the fuel gauge shows empty and I go fill it up, I only register about 40L.  Does anyone know the exact problem?  is it pricey?

If I don't fix it, what are some of the strategies that I can use to prevent running out of gas?

Henry

Most vehicles show "E" before the tank is really dry as others have said above. Why bother fixing it? It's not smart to run your tank dry anyway - just gas up always when you are below the 1/4 left mark. No big problem, IMO.

As to running out of gas, if you are the type that has to drive it until the "E" light comes on, then you probably deserve to run out of gas. Like Kramer in Seinfeld.... right? Just gas up below 1/4. 

[mmret]

This does raise one interesting question though. Does the "distance to empty" / range computer speak in terms of real empty, or gauge empty?

[haijing]

This does raise one interesting question though. Does the "distance to empty" / range computer speak in terms of real empty, or gauge empty?

Yeah, that was one of my other concerns, will the car quit on me because the gauge says empty or will it keep going until the tank is dry?

[si]

top gear season 4, episode 4, had jeremy clarkson seeing how far he could get an Audi A8 diesel on one tank - ended up driving well into the minuses of the computer's 'distance-to-empty'

[AVToller]

Yeah, that was one of my other concerns, will the car quit on me because the gauge says empty or will it keep going until the tank is dry?

  The engine will perform based upon reality, NOT what the gauge says. If you still have gas, the engine will run.    But having said that, there are several good reasons to not let the tank get very low.

[haijing]

thanks guys!!!!!!!!!!!!!!

[mmret]

This does raise one interesting question though. Does the "distance to empty" / range computer speak in terms of real empty, or gauge empty?

Yeah, that was one of my other concerns, will the car quit on me because the gauge says empty or will it keep going until the tank is dry?

Like others have said, the car will certainly run. I was more concerned about how "true" the DTE is.

[articsteve]

When filling up to the top reset trip odometer and experiment.

[dr_spock]

Doesn't the Altima come with a low gas warning light? 

[Trainman]

Doesn't the Altima come with a low gas warning light? 

My Pathfinder does and it takes about 65l when the light comes on.  Its a 80l tank    At half showing on the gauge, it takes 30l, not 40.

No on board computer to worry about "distance to empty"   

Maybe a Nissan thing   

[barrie1]

My 91 Caddie drops like crazy when its on the full mark. When I hit around 5-6 gals of fuel it just sits there for a week or so on normal around town driving. Even on the 2 gal mark it  will take a good amount of driving to set off the warning light. I have purposely done this recently as its a new fuel tank I know that i won't have much dirt or water in the bottom to be sucked up and give me problems. I normally wouldn't do this but it nice to know just how your gauge works and wether its high or low on the amount left in the tank. I agree never do this as a habit as you will run into trouble sooner or later. 

[johngenx]

The Subaru fuel gauge is very pessimistic, showing 1/8 of a tank remaining and taking 43-45L of a 60L tank.  But, it still has to drop to E and then show the fuel light.

The Mercedes' fuel gauge is typical German anal-retentive, in that at 1/2 tank, it takes 30L of the 62L capacity.  At 1/4 remaining, it needs 45L to fill, and so on.  The manual states that the reserve light will come on with 55L of fuel consumed of the 62L.  If you get gas right after the fuel light comes on, you'll put 55L in.

All of the Japanese-brand cars we've owned have had pessimistic gauges, including Mazda, Honda and Subaru.

[si]

while we're on the topic, I get great milage on the first half tank, and bad milage on the last.  I think this is due to tank shape.

Furthermore, I can go over 100km before my absolute "full" reading drops a bar.

[random006]

Fuel gauges are not linear in their behavior.  This is quite possibly due to tank shape, as SIVIC states.

The first 1/16 of fuel usage (full down to 15/16 of a tank) seems to last as many kilometers as the next 3/16.  Then a relatively quick drop to 1/2 followed by a slow down.

During that time, if I've shut the engine off for any significant time then upon starting up the car and driving, the gauge will rise slightly over the next 5 or 10 kilometers to its true value.

As far the low fuel warning, my car's manual says it will come on with 12 litres remaining of an 80 litre tank or 15% of capacity.

[barrie1]

I think all makes have their quirks in these area's as no 2 gas tanks will work the same. As long as you learn the habits of yours then you shouldn't be running out of fuel at any time. In the winter in particular I always fill up at 1/2 tank and no lower.   

[tpl]

There is no reason apart from poor engineering and bean counters why fuel gauges should not be accurate for 90% of the range at least. Even if the float and potentiometer is not perfectly accurate the fuel metering system in the ECU should be able to interpolate that to give a good reading.

[johngenx]

There is no reason apart from poor engineering and bean counters why fuel gauges should not be accurate for 90% of the range at least. Even if the float and potentiometer is not perfectly accurate the fuel metering system in the ECU should be able to interpolate that to give a good reading.

It can be done.  My MB's fuel gauge is deadly accurate.  All of the MB's we've owned have been.