exrub

Hello, all!

I want to know if anyone else has noticed this...no it's actually not about fuel economy.

I have a '12 V6 Convertible that I bought used. The average mpg shows 19.3 (after reset). I do not really argue this since I do mostly city driving but have to keep up with traffic on the highway. However, the miles to empty is what throws me off.

After several fill-ups, the reading would show about 275 miles to empty. By my calculation, 16 gallons @ 19.3 mpg should be about 308 miles. Vice versa, if I divide the 275 miles by 16 gallons, this yields 17.2 mpg.

Does the countdown actually cheat by hiding a portion in reserve so the driver does not actually go empty?

Now, I also have a new '13 V6 Coupe that I have only filled-up once so far. She doesn't get driven much for now. When I filled her tank, the reading showed about 305 miles to empty which would be closer to the calculation.

Anyone have any insights on this?

Thanks!

CiniZter

all i know from my past experience is ... i drove 9-10 miles when it showed 5 miles to empty... after 5 miles to empty, Guage just freezes and did not go down... so i just kept on going....did that to empty out the 87 gas dealership put in.... had my wife follow me just in case i need to be towed..

FordService

Hello exrub,

I recommend you bring it in to your Ford dealer and have it looked at. Your Service Manager is in the best position to look into this for you. He can check into any warranty, Recalls, or Customer Satisfaction Programs that may apply to your vehicle. Let me know the outcome.

Deysha

exrub

Hi, Deysha.

I plan to pose that question the next time I take her in for service which should be in a couple of weeks.

BTW, I am pleased to see that you and a couple of others are always on here to help out the owners. Keep up the good work!

FordService

Thank you, exrub!

Deysha

cdynaco

First, have you read your manual? Second, do you reset all the parameters at fill up, or just the average fuel economy?

My 08 manual says the DTE is calculated over the past 500 miles, whereas the AFE is more recent mileage.

And yes, I assume the DTE leaves the 50 miles to empty reserve out of the calculation. Otherwise it defeats the purpose of the reserve and the alarm.

No doubt your instructions are different than 08, but here's what mine says:

Distance to empty (DTE)
Selecting this function from the INFO menu estimates approximately
how far you can drive with the fuel remaining in your tank under normal
driving conditions. Remember to turn the ignition off

The DTE function will display LOW FUEL LEVEL and sound a tone for
one second when you have approximately 50 miles (80 km) to empty. If
you RESET this warning message, this display and tone will return
within 10 minutes.
DTE is calculated using a running average fuel economy, which is based
on your recent driving history of 500 miles (800 km). This value is not
the same as the average fuel economy display. The running average fuel
economy is reinitialized to a factory default value if the battery is
disconnected.

Average fuel economy (AFE)
Select this function from the INFO
menu to display your average fuel
economy in miles/gallon or
liters/100 km.

If you calculate your average fuel
economy by dividing miles traveled
by gallons of fuel used (liters of fuel used by 100 kilometers traveled),
your figure may be different than displayed for the following reasons:
• Your vehicle was not perfectly level during fill-up
• Differences in the automatic shut-off points on the fuel pumps at
service stations
• Variations in top-off procedure from one fill-up to another
• Rounding of the displayed values to the nearest gallon (0.1 liter)
1. Drive the vehicle at least 5 miles (8 km) with the speed control
system engaged to display a stabilized average.
2. Record the highway fuel economy for future reference.
It is important to press the RESET control after setting the speed
control to get accurate highway fuel economy readings.

WhiteBird00

Really? Why? Octane ratings average when fuel is mixed - that's how most stations sell mid-grade without having a separate tank in the ground. So if you filled up with 93 octane when there was about a gallon of 87 left, you would have 92.625 octane fuel in the tank... certainly close enough for even a picky tune without having to risk running out of gas.

CiniZter

I didn't know that....I was stupid to do run around to empty it out....my wife was mad at me for doing it.

WhiteBird00

Better not tell her now... no need to stir the pot.

exrub

Hey, cdynaco.

First, yes, I have read the manuals for all seven vehicles and two motorcycles in my current fleet. Also, I have read the manuals for all of my numerous previous vehicles.

Second, no, I do not always reset the parameters at fill-up. Normally, I keep an eye on the longer term averages rather than the recent calculations. I reset the AFE on the prior fill-up to see if there would be a difference in the average...which there was none.

I have noticed that each of my other types of vehicles have their own intricacies. For example, my Mariner does the warning at 50 miles to empty. However, it still lies to me about an approximate 1/2 gallon reserve; meaning there's still about another 10 miles in addition to the 50 miles. Also, my Focus is even different from the Mariner when it comes to this function.

Lastly, if you note, I did a comparison between my 2012 V6 Convertible to my 2013 V6 Coupe. I would think the range would be similar on these two since the AFE is similar.

exrub

I can imagine your wife was ticked.

Definitely don't bring it up again. If she does, just tell her that you needed her to see if the car showed any problems when in motion.

My wife still reminds me about having to bring my gas container 1/2 mile from home when one of my cars ran out of gas on an uphill incline just across the street from the gas station.

AzPete

They just need to go back to .... it is empty when the needle is on the E . Why ever bother to run a car that close to the empty mark and possibly create more work for yourself.

tukatz

I just refueled this morning and recorded info from both trip meters. Miles to empty displayed as 41.
Trip A showed 262.5 miles covered with an average of 20.4 MPG and 12.8 gallons used.
Trip B showed 523.8 miles covered with an average of 19.9 MPG.
The pump shut off after 12.519 gallons. This seems fairly consistent - the gallons used always displays a little higher than the gallons pumped.
If I use the approx 500 mile average it tells me that I had 2.06 gallons until empty. Add that to the gallons pumped and I get just a bit shy of 14.6 gallons. My conclusion is that when the display reads empty I will still have nearly 1.5 gallons.
I don't intend to push it, but I am more comfortable using all those miles to empty if the nature of my drive calls for it.

WhiteBird00

Having grown up in Canada during a time when there was no such thing as cell phones, I learned to never let the tank get below half in the winter or quarter during the summer. Now that I live in Florida, I seldom let the tank get below half during the summer either (never have to worry about getting out of town in the face of a hurricane). In fact, even after all these years, my palms get sweaty if my fuel gauge starts getting close to the bottom quarter. I have never seen the low fuel warning on any car and the DTE is merely a curiosity. But I've never run out of gas or regretted not being able to go further to find a different station to buy from. And it seems easier to part with $25 for a half tank fill-up than to wait longer and have to dig deeper for a fill-up.

So I guess I don't understand the interest in how far you can go on an "empty" tank.

cdynaco

The reason I asked is because when I don't reset all the parameters (avg speed, etc.) the AFE has a wider difference than actual math from a fill-up. When I reset all of them, the AFE is pretty spot on to actual mileage.

tukatz

When I go on a road trip I plan my driving days based on how long I feel like being in the car and where I would like to stop. That frequently translates into a number of miles that approaches the car's range. I can then fill up at my end-of-day stop rather than having to do so twice during the day. The places I stay for a night are usually larger towns where gas is likely to be less expensive than it is out in the boondocks.

exrub

Interesting. I just thought it was odd how the two V6s differed.

Here's a thought...the 2012 being a former rental, I wonder if one of the people who rented it stuffed some valuables in the tank. Hmmm!

WhiteBird00

There is a big difference between planning based on expected range and pushing to the last drop of fuel. I'm sure you don't plan your trips to stop only when the dash says 0 miles to empty. Personally, I fill up more often than that on a long trip because at my age I need more frequent stops to stretch my arthritic legs.

Moustang

Every new car sold today will tell you the tank is empty with 1-2 gallons still left in the tank. Generally speaking you can drive virtually any car between 25 to 50 miles on the highway after hitting empty.

Your car has what is called an "empty reserve" and it also has a "full reserve" which is why when you fill the tank up the needle will sit at F for nearly 50 miles without moving. Your gas gauge is really only measuring about 12-13 gallons of fuel with 2 on top a 1-2 on the bottom which are not counted.



I've run every car I've ever owned out of gas at least once deliberately. I take long road trips across empty country and desert, and I've always felt it was important to know precisely where that limit is in case I ever needed to really push it. I got 56 miles out of my V6 Mustang after it hit "0 Miles to Empty".

exrub

Hi, Deysha.

I PM'ed you yesterday regarding another issue. Not sure if you've had a chance to read it yet, but I would really appreciate your assistance on it.

Thanks!