I don't take the reading seriously, but I do use it as an indicator. Working for a Ford dealer, many cars we receive are low on gas and when I see 15mi or less remaining I generally put them aside to get filled. However I do know that you can still go a good distance when it says 0mi till empty, I know of several that have been driven around the lot, through service, and still made it the 1.5mi to the gas station while saying 0mi.