I haven't had the truck all that long. Still getting used to it, and it's quirks.

Last night, I put some gas in it. Didn't top it off, but when I got back in the cab the gauge was about a needle's width below the full line. I drove about 35 miles yesterday evening after getting gas and when I got home, the gas gauge was about a needle's width below the 3/4 mark.

Now, unless my truck is getting HORRENDOUS fuel mileage (which I doubt), the gauge must be off.

Do any other owners have inaccurate fuel gauges? Is this a known problem?

 

Don't leave the key in the on position when fueling, the needle may point anywhere.

 

I didn't leave the key in the on position. Never do. The truck was fully OFF and the key was removed from ignition.

 

Mine is very acurate. I have a44 gal tank. Each 1/4 is 10 gallons almost exactly. When I'm at 1/4 tank I have 14 left. It's been the same for the two years I owned it. Once I had 200 miles at 3/4 tank. Some don't believe me but that worked out to be 20 mpg. It trust my gauge. Try filling it all the way and see what happens.

 

My 2008 has had issues off and on with the guage being way off. Sometimes with a 3/4 full tank it will tell me it's empty and I have to fill up again to make it show total full, then it may work fine for a while. At 115,xxx miles, the sensor may be tired.

 

I've noticed that most gas gauges are very quick to come off of FULL and then slow down more and more until it gets near EMPTY.

Reason being the float, the height of it's pivot point, and the angle the float travels through as the level goes down. The sensor is a resistor like a volume control. If it's linear, the rate of change will be faster near FULL, and slower near EMPTY, if the pivot point is near the top of the tank.

The only way to tell real fuel mileage is to fill it until the pump clicks off, drive it for a while, go back to the same pump and fill until it clicks off. Record the gallons pumped, and divide miles traveled by the number of gallons. It helps if the ambient temperature is close to the same at both fillings too...

 

My needle drops quicker it seems in my 05. There's times when it says I'm just below half tank and iI fill it up and it takes in the high 8-mid 9 gallon range to fill. I have the 29 gallon tank and technically half will about 14.5 gallons. I just fill up normally when I'm near a quarter tank.

 

Make sure the rubber lines to the charcoal canister are clear. Does the air whoosh into the gas tank when you open the cap?

 

My 02 is the exact same way. Lucky to get 50 miles out of the first 1/4 tank. It has been that way since new. The complete opposite for the final 1/4 tank. That will go a long way.

 

A watched pot never boils, well a watched fuel gauge drops like a rock and 10 cylinders certainly doesn't help. Or maybe that's just from sitting in the truck to long on these long drives.

 

I've had my truck two and a half years. The gauge has only been up to full one time. In Oregon we aren't allowed to pump our own gas, and attendants can't top it off. The one time it actually went to full it took the gas attendant about 5 minutes of topping to get it there. She put in almost 6 gallons after it shut off.

 

With patience, I can usually get another 1.5 gals after the auto shut off.

 

Political comments removed. We don't need that stuff here.

 

weird... my gas gauge will sit at max refuel for quite awhile, start to drop quickly off of full.

slow down again just before 1/2, then drop like it has a leak after 1/4...

samething everytime..

 

My 02 Excursion is the exact same way. It drops fast from full to 3/4, a little slower from 3/4 to 1/2, then it takes a long time to drop from 1/2 to 1/4 and 1/4 to E.