When the information center on my 07 F150 King Ranch indicates I am empty I can only pump 26+ gallons in to the "30 gallon tank"...what gives...can the onboard computer be adjusted...is is possible the wrong tank was factory installed?

 

On my KR the computer center is inaccurate. The MPG is off by almost 4 MPG.

There have been several posts on this board about the message center being so inaccurate, so it does not surprise me yours is also inaccurate.

I log all my gas vs mileage the old fashion way. Works for me and is very accurate.

 

You need to fill your tank exactly when that indication comes on. My wife used to pride herself on her ability to coast into gas stations on fumes. Then we forked over about $800 to replace the in-tank fuel pump, which is cooled by the fuel itself. Those remaining six gallons prevent your pump from overheating!

 

Well, it's around six for me (and most I've heard from), but apparently only four or less for you. And even if your pump wasn't cooled by the fuel, you wouldn't want it coming on when you were truly empty, would you? You'd know that when it stopped going forward without pushing it! Remember, these are "idiot lights" and the equivalent thereof. They're meant to warn you long enough in advance for you to actually do something about the problem...

 

Back in my "SD" days they called the info center the "lie-o-meter" . Mine is never close on mileage so I just figured it can't be close on amount of fuel remaining either. I usually have about 6 gallons left when the "your almost out of gas " message comes on. I usually only let it get that low if my wife is with as she was a helo pilot and she gets flipped out if the gauge goes below a half tank One other issue is that I have the 36 gallon tank option so unless I want to plan a lunch break while I fill up I usually don't let it get that low!

 

I understand how your wife feels.....
I once had the low fuel light come on in my plane whilst flying over Manchester on a flight from Scotland to the south of England...

That's when you get worried, not when it comes on in a vehicle where you can just coast to the side of the road.
I was actually looking for spare bits of freeway (Not a common sight around Manchester) to land on.