Bushguts

I have a little over 1k on my car. When it says I have 15 miles left I go and fill up and it takes 13 gallons. Why is it still off after this kind of mileage. And my gas needle is on E while this is happening. I can't judge how many miles I truly have left. This is a pain because I'm spending money too soon.

Does this happen to anyone else? If so what did you do to fix this? It's so annoying.

watchdevil

It is very important to not let the fuel tank run dry or you will burn up the fuel pump or encourage possible sediment in the tank to stir up and clog the pump. Ford designs in the margin of error for idiots who insist on going as long as they can without filling up. The Mustang gives plenty of warning at 50 miles left, then at some point when it gets even lower it turns the fuel gauge bright red. I will often reach the 20 miles left mark. When I fill up it's almost always between $48-$50. Really you have nothing to complain about unless you just want to be stupid and burn up your fuel pump.

Bushguts

I'm not complaining. Just looking for accuracy.

watchdevil

Try exercising arithmetic you learned in grade school... 13 gallons to fill... That means you have 3 gallons left in the 16 gallon tank.

Bushguts

you must not be good at math. so let me educate you. if this car gets 15mpg then that would mean i have 1 gal of gas left. and it should take 15 gal upon fillup.

did you come in here to break ***** or help. if your not going to be any help then dont comment

watchdevil

You must be assuming that the 15 miles-to-empty readout is accurate along with the fuel gauge, which you have already proven that they are not by stating at 15 miles-to-empty it took 13 gallons to fill up your 16 gallon tank.

This also means your 15 MPG average figure in the info center may not accurate because the info center uses the data from fuel gauge sending unit and odometer to determine MPG and miles-to-empty.

The tank is 16 gallons and you said it took 13 gallons to fill it. That leaves you with 3 gallons left in the tank before you filled it. That is real math (16 gals - 13 gals = 3 gals). There is no other math in the world that can say you had less. Please explain how it can physically be any less?

Where are you getting your figure of 15 mpg from? Actual MPG is an average that can only be determined by dividing the number of miles traveled since the last fill-up by the number of gallons of gas used to fill-up the tank again. If you want accuracy, doing calculations this way is the only way you are going to get it.

Assuming your vehicle in fact gets 15 mpg then that means before you filled it up it had a remaining 45 miles range left for travel (15 mpg x 3 remaining gallons = 45 actual remaining miles to empty). If you filled up using 13 gallons of gas, that means you traveled 195 miles since your last fill-up (15 mpg x 13 gallons = 195 miles). Your entire tank travel range at 15 mpg is 240 miles (15 mpg x 16 gallons = 240 mile tank range).

As I said earlier, Ford designed a margin of error into the driver information system so idiot drivers don't run the tank completely dry and burning up the fuel pump. There is nothing that can be done to give you an truly accurate fuel gauge reading. It's not a defect nor is it something that can be "corrected" just to satisfy you. This is completely normal for every Mustang. I have owned two S197 Mustangs, a 2008 and my current 2010 and the fuel gauge, miles-to-empty and MPG info functions exactly the same.

I have had 18 different cars of various makes and models over the past 32 years and none of them have ever had an "accurate" fuel gauge.

AndreaCristiano

Why is everyone being such douches? The guy is just asking a question!

Rog13GTCS

I get the 50 mile to fillup early, and I ignore. I havent done anything to fix or change it.

I check the Trip a/b - I found that it give me a close picture of where I'm at. I filled up the other day and it said I used 12 gallons and I put 12.3 in. Not 100% accurate, but gets me in the ballpark. Just remember to reset at fill up.

I did find this thread talking about the same thing. Hope that helps.

AndreaCristiano

I find this method is also much more accurate