Do our cars have a 2 gallon reserve once miles hit 0?

[Stormtrooper5.0]

I fill up when I'm close to half-tank which is usually every sunday. I've never seen the gas light come on in my 15 months of having my v6 but for me, anything less than half...is empty. $15 for half tank is splendid.

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[GT Pony]

If you reset the trip meter info at every fill-up then previous gas tank fulls shouldn't factor into the computers predictability. I always reset the trip meter after each fill-up, which also resets MTE and avg MPG.

That is incorrect sir.

Ford's DTE calculation is based on your last 20 miles worth of driving.

Example....if you just filled up 14 gallons after a day of autocross runs, your DTE may only read 230 miles.

If you just got off the highway and had been on a long road trip getting 24mpg, your DTE will be close to 400.

You are talking about what the DTE will read after a fill-up, and I agree it may react like you described above with an after fill-up DTE value.

But I was saying previous gas tanks don't factor in especially if you reset the trip meter at fill-up. Resetting the trip meter also helps you achieve a more accurate avg MPG for the present tank of gas. In your example, once you start driving the DTE will start to home in on what the real DTE is on that tank of gas if your driving style is pretty constant.

But if say you were getting close to empty and then you all of a sudden started driving like a mad man then the DTE could be thrown off since it's supposedly only based on the last 20 miles of driving.

So the hint here is before going wild with the throttle with a low gas tank make note of the DTE and know it might become inaccurate if the driving style is drastically changed.

 

[awmustang]

If you reset the trip meter info at every fill-up then previous gas tank fulls shouldn't factor into the computers predictability. I always reset the trip meter after each fill-up, which also resets MTE and avg MPG.

In all previous Ford's I've had, the Miles to empty is based on a rolling 500 miles of average MPG and is not resettable when resetting the trip. If resetting the trip actually made a difference you would see the miles to empty jump around like crazy when you first reset it because the average MPG would be changing so wildly due to the short time frame the average is over. I suppose it could reset to some preconfigured value rather than 0, but that would still cause the miles to empty to jump when it switched from your actual values to the preconfigured ones.

From previous Mustang manuals.

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.

 

[GT Pony]

In all previous Ford's I've had, the Miles to empty is based on a rolling 500 miles of average MPG and is not resettable when resetting the trip. If resetting the trip actually made a difference you would see the miles to empty jump around like crazy when you first reset it because the average MPG would be changing so wildly due to the short time frame the average is over. I suppose it could reset to some preconfigured value rather than 0, but that would still cause the miles to empty to jump when it switched from your actual values to the preconfigured ones.

From previous Mustang manuals.

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.

There is no such language in the 2015~2016 Owner's Manual. This is all they say from the 2016 OM. Maybe someone that has a full factory Service Manual could see if there is more detailed information on exactly how the DTE works on a S550.

 

[Gman]

One of the best Seinfeld episodes ever was where Kramer wants to drive as far as he can before running out of gas, it was a classic.

Terry

One time I got in my car after a client meeting and it read 0 miles left but it said 3 miles when I parked it. I had to stop in to see another client about 1.5 miles away right after the first meeting so I figured I was well beyond safe holding off until afterwards to fill up.

Boy, was I wrong. I left my second client's place and began driving to the closest gas station which was no more than 2 miles away. Ran out of gas while sitting in line at a stop light, when I was only about 20 yards away from the entrance of the damn gas station. I got out and started pushing in 95 degree heat while wearing business attire. Luckily, the person behind me was kind enough to help.

Haven't trusted my car past 0 miles since.

Seinfeld episode with Kramer on gas

 

[Dominant1]

Woulnt know i always fill up when i get down to a 1/4 tank...makes me feel like gas is cheaper..lol

 

[Road Dog]

There is no such language in the 2015~2016 Owner's Manual. This is all they say from the 2016 OM. Maybe someone that has a full factory Service Manual could see if there is more detailed information on exactly how the DTE works on a S550.

The section on variations is what I was talking about. Your most recent MPG rate is what is compared to the fuel in the tank to determine the DTE. So if you change the way you drive to drop the MPG drastically with very little gas in the tank you can expect the DTE to also drop drastically and it could result in running out of gas sooner than you expect. Knowing this should help you plan your gas stops to minimize the chance of getting in trouble. :hail:

 

[jvandy50]

One time I got in my car after a client meeting and it read 0 miles left but it said 3 miles when I parked it. I had to stop in to see another client about 1.5 miles away right after the first meeting so I figured I was well beyond safe holding off until afterwards to fill up.

Boy, was I wrong. I left my second client's place and began driving to the closest gas station which was no more than 2 miles away. Ran out of gas while sitting in line at a stop light, when I was only about 20 yards away from the entrance of the damn gas station. I got out and started pushing in 95 degree heat while wearing business attire. Luckily, the person behind me was kind enough to help.

Haven't trusted my car past 0 miles since.

this happened to me also, tank said 50 miles to empty, i had a 30 mile drive to make...dropped a buddy off, ran out of gas literally feet away from the gas station. just had knee surgery, pushed her uphill and over to the side. thank god a nice guy got out and helped after i got it rolling. boy was i sore and my dad couldn't wait to say "boy what'd i tell ya bout runnin em low and how it's hard on em!"

 

[isedawishy]

When I was transitioning from 93 to E85 I took the long way to the gas station because it said 15 miles left. Car died at 14 miles to go...

My gas can back home was full of E85, so had my GF bring it to me and I had to load the initial E85 tune on the side of the road... at night.

Guess what happens when you load your tune... no power, to anything... including hazards.

It happened with an aftermarket fuel system to be far, probably makes a difference of some sort. I still told Lund he was a dick for telling me to go down to "0", haha.

 

[superman07]

That is incorrect sir.

Ford's DTE calculation is based on your last 20 miles worth of driving.

Example....if you just filled up 14 gallons after a day of autocross runs, your DTE may only read 230 miles.

If you just got off the highway and had been on a long road trip getting 24mpg, your DTE will be close to 400.

That doesn't seem right, with e85 I can go from 8mpg to 18mpg city / freeway, and the DTE definitely has a smoothing algorithm. Only adding gas resets the DTE in any meaningful way. I can run the car hard and with a full tank register 160 miles to empty, take it out on the highway for an hour and a half to my office and the DTE sits stubbornly in that range. The miles driven does not match what is registered so it is factoring in the difference, but not to where in 20 miles it has decided my DTE is now over 160.

 

[superman07]

this happened to me also, tank said 50 miles to empty, i had a 30 mile drive to make...dropped a buddy off, ran out of gas literally feet away from the gas station. just had knee surgery, pushed her uphill and over to the side. thank god a nice guy got out and helped after i got it rolling. boy was i sore and my dad couldn't wait to say "boy what'd i tell ya bout runnin em low and how it's hard on em!"

My dad refused to drive a car under 1/2. We were driving through Montana once in a new car and thought we were getting great mileage, Thank god he knew better and decided to pull over, we were almost out of gas as the tank had a bad sending unit.

 

[NightmareMoon]

From previous Mustang manuals.

DTE is calculated using a running average fuel economy, which is based
on your recent driving history of 500 miles (800 km).

Yup that sounds about right for my experience. Seems to take it a tank or two to adjust and return to normal predictive behavior after a track day. It definitely doesn't fully adjust after only 20 miles.

 

[timd38]

One of the best Seinfeld episodes ever was where Kramer wants to drive as far as he can before running out of gas, it was a classic.

Terry

I remember that one! It was a Saab......

 

[hollywood37343]

put 16.2 gallons in a 15.5 (stated capacity for EB) tank. average MPG was around 16 MPG per the trip computer (short distance commuting). DTE was 5 miles.

???

 

[Falcon01]

I filled up my Ecoboost 14.998 gallons with 8 miles to empty averaging 20.6 MPG. So no, there aren't 2 gallons. I don't even know if there is one gallon.

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