Gas tank capacity less than 23 gallons

[Inv4drZm]

^ What he said. I get a pretty consistent 2 additional gallons in (slowly) after it shuts off the 1st time.

I heard somewhere that can damage the tank/sensors.

 

[kevinpt]

i have gome to 0 miles and only filled up 21 gallons

 

[Bluesky 07]

The never ending OBC fuel guessing game. Let just say this, my first 04 t4r I bought was fresh off the lot. This same gauge stated 420 miles to mty. Within a yr later, mind you no lift or other mods to it to decrease the mileage, it would read 340 till mty.

I say your best bet and has been more than accurate other than hand calculate is, when the light comes on, your at 20 gal fill up.+/- .5 gal.

This is exactly why I was reading this thread. Bought my '07 Sport V6 in November 2014 with 96K miles. Until two months ago, the range always read 400-420 after a fill-up. Then one day it only went to 365. I thought I might have gotten a false cutoff from the gas pump so the tank wasn't completely full but that's been the norm on the range display ever since.

There was no "trigger" I can think of - no engine work, etc. - that might have caused it. The only change around that time was installing a new head unit, for which I didn't disconnect the battery but did of course remove the range display panel. But I've done that several times before with no effect on the range readout.

MPG is constant at 18-19, and I measure it by resetting the trip odometer to zero at fillup and dividing that by the amount of fuel added at the next fillup.

I get that the range display in any vehicle is not 100% reliable but the tank capacity x my average MPG for 1.5 years is around 400 so I found the sudden fall to be odd.

On another display-related note however, the average MPG reading is always 21+ and we all know better than that.

 

[2fullgarage]

^^^ Same thing happened to me. Disconnected the battery Sunday to reset the rear door ECU, and now the "estimated mileage remaining" in a full tank dropped from 406 to 325? WTF