which to trust more: fuel gauge or little orange 'low' fuel light...thingy

[Ramma2]

Your owners manual will tell you the capacity of your fuel tank. A person should be able to figure it out from there.

 

[amicold]

In my Buick Regal the tank is 17 gallons, but my light comes on with 4.5 to 6 gallons left. Go figure.

 

[Evadman]

My truck has a 'miles to empty' thing in the trip computer. I drove it for 45 miles after it read zero because Iw as in the middle of fricking nowhere.

<edit>
I should probably point out that at that time Iw as getting about 7 to 8 MPG. So there was a lot left.