I have observed lately that when the empty/low fuel indicator light comes on and I go for a refill, I can only get 15-16 gallons in the tank. On occasion I have been able to get as much as 20 gallons in (which sees more normal)

Also, sometimes it seems as if the gauge needle and the digital miles to empty "stick" as I get to the last quarter tank i.e. let's say the needle is at a quarter and the digital gauge says 80 miles remaining as I am parking the car. When I return later and restart, the needle drops a bit lower and the digital display now says 40 miles remaining, so on and so forth.

Did not do this before, started around 55K miles. Could it be a float sensor in the tank? Easy fix?

 

That would be my guess. My 96 XJR did the same thing and it was the fuel sensor.

 

Anyone else have any ideas?

 

The fuel low light for USA cars is set differently than European cars. It seems that the folks in the USA tend to ignore the light more than the folks in Europe. Go figure!! If this had been the normal, I would have just checked it off as normal, but since it seems to be a change for you and the symptoms are changing after sitting for a while, then I would have to agree with Drew.

 

My X350 does the same thing but I've noticed it "self-curing" in the past cpl weeks. I actually let my fuel run down to the 0-2 miles to empty range, did a 3/4 fillup, then normal fillups afterward and the problem seems to have cured itself.

Gotta admit, the first time it happened after I dumped over $50 in fuel in the car and noticed less than half a tank showing I got a bit alarmed at its seemingly increased "appetite". Lol.

 

I filled my 04 this morning with 14.5 gallons, I had about 1/4 left and the computer said I had about 118 miles left on the tank. I know the 96 is a different car, but it did act the same way. I think the signal from the sensor goes to the computer and guage. The miles left in the tank alway matched what the guage said.

 

That's why I always keep a container of Spare Fuel in my car now.

My fuel gauge doesn't work properly like so many others.

Check it out.

http://www.sparefuel.net