Anyone using Distance to Empty?
03-01-2014, 03:41 PM
#31
Senior Member
That's pretty much the only screen both my wife and I use on our vehicles. I'll generally fill up below 50 to maximize Kroger points unless we have bad weather forecast.
03-01-2014, 03:44 PM
#32
Senior Member
I didn't get the 36 gal tank to only use 15-20 gal. I use every bit I can, and run it down to 20-30 miles to E every tank. I don't buy into the "it's hard on fuel pump and engine to run tank empty all the time" mantra by some guys here. Always ran vehicles very low and have never had a problem....but, I try to buy from large well known stations.
03-01-2014, 03:48 PM
#33
Truth doesn't care if you believe it or not. The pump is cooled by the fuel in the tank. Excessively and repeatedly running it low will reduce the life of the pump. How low is low? Good question. Less than an 8th seems reasonable.
03-01-2014, 04:49 PM
#34
Senior Member
To cool and lubricate the internal components, fuel must flow continuously through the fuel pump. Insufficient flow limits cooling and lubrication of the pump. A leading cause of fuel pump failure is running the fuel tank low. This is particularly critical on late model vehicles without a fuel pressure return system. Running such a vehicle out of fuel once can permanently damage the fuel pump.
03-01-2014, 04:59 PM
#35
Senior Member
Uhuh, and how do you explain multiple Ford gas trucks run close to empty for at least 150k per truck with no adverse fuel pump issues? Mr. fuel pump police.
03-01-2014, 05:03 PM
#36
Maybe you are lucky. Maybe you weren't running it as low as you thought because the manufacturers are aware people don't read the manual so they build in a reserve capacity (I suspect this is true).
Maybe it did just what I said. Reduced the expected life of the pump. Perhaps the pump would have lasted 300,000+ miles, but yours was only good for 200,000.
03-01-2014, 05:07 PM
#37
Regardless, you are correct. And unless you're running it low enough that it sputters or stalls then the damage, if any, may be marginal.
Once I was low on fuel offroading in my old truck (had 160,000KM) and on the wrong angles it would sputter a bit. A couple months later my fuel pump died on me.
Coincidence? Who knows, but I don't run my vehicles that low if I can avoid it.
03-01-2014, 05:15 PM
#38
Senior Member
Easy.
Maybe you are lucky. Maybe you weren't running it as low as you thought because the manufacturers are aware people don't read the manual so they build in a reserve capacity (I suspect this is true).
Maybe it did just what I said. Reduced the expected life of the pump. Perhaps the pump would have lasted 300,000+ miles, but yours was only good for 200,000.
03-03-2014, 01:21 AM
#39
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I have only owned and operated one vehicle with a trip computer. It had one only because I built it. I manufactured and sold trip comuters for BMW K model motorcycles from '91 to '08. The product name was Fuel Plus. I say was because the recession killed the after market business for me.
A trip computer cannot predict changes in consumption but it can calculate on the fly and give an accurate DTE while consumption varies. Occasionally I would discover my range was close to the distance to a town that should have fuel. A decision I made one Sunday afternoon at an isolated convenience store was to not buy fuel there because 1. no premium, 2. I didn't trust the fuel to be water free. I showed 35 miles remaining on the tank and the distance to the next town was 35 miles (posted). Don't trust all mileage signs! I chose to run to the next town because I knew I could make it. My trip computer has a tracker feature. Enter the destination (35) and it will give the difference of range and remaining distance (+ -) miles. Zero or positive is what you want. I had gotten to negative one and had to slow down to catch back up. Catch up must be done early enough to have enough distance to gain it back. I backed off to 55 for about 5 miles to get back to zero. The range showed one and the motor was still running at the pump.
That being said it's not my preference to run it close but when needed you have to know if the computer is telling the truth to rely on it. I intend to tow my boat to the lake and back each trip. Currently I can make it on one tank in my old truck. I have no idea if the F-150 will do it. It's one stop I don't have to make if it will. It's not a big deal if it won't but if it's close I want to know so I can make the decision where to stop.
I don't know how Ford programmed their computer but I suspect the range is not calculated from the economy figure. They publish that the average distance for DTE is 500 miles. That should be a running average. There is no reset for that as it is taking the last 500 miles consumption and multiplying the fuel remaining to get the range. Anyway that's how I do it EXCEPT not for 500 miles! It needs to be more like 40 miles to allow changes in consumption to filter into the calculation. That will give you an update much sooner.
In my testing on the motorcycle I ran the tank empty several times. As for overheating the pump motor, it cannot run out of fuel because when the pressure drops the engine falters and quits which powers off the pump. Never had a problem. I can't say what the Ford will do but I will find out and let you know.
My experience with fuel tank capacity has been that the manufacturer states the WHOLE volume of the tank. The usable volume is the whole volume minus the pump and other parts inside, minus the volume below the pickup tube. My Chevrolet Duramax had a stated volume of 36 gallons. Actual is 34. That can only be determined by running it empty then measuring the fill-up volume. I will do the same on the F-150.
If Ford is using the gauge float for measuring it can't be accurate. If they are using the injectors for measuring it can be accurate. If they are actually averaging over 500 miles the average is not useful. My computer was user selectable from 1 mile to .... can't remember the limit but much higher than is useful.
I have not emptied the first tank yet and it will be awhile if this weather keeps me off the road.
I have a couple of questions. The computer stores normal history and towing history. How does it tell there is a trailer? Do I need to select which history to use in the settings when I am towing? The manual does not explain. See page 124, DTE calculation.
Thanks for all your input.
A trip computer cannot predict changes in consumption but it can calculate on the fly and give an accurate DTE while consumption varies. Occasionally I would discover my range was close to the distance to a town that should have fuel. A decision I made one Sunday afternoon at an isolated convenience store was to not buy fuel there because 1. no premium, 2. I didn't trust the fuel to be water free. I showed 35 miles remaining on the tank and the distance to the next town was 35 miles (posted). Don't trust all mileage signs! I chose to run to the next town because I knew I could make it. My trip computer has a tracker feature. Enter the destination (35) and it will give the difference of range and remaining distance (+ -) miles. Zero or positive is what you want. I had gotten to negative one and had to slow down to catch back up. Catch up must be done early enough to have enough distance to gain it back. I backed off to 55 for about 5 miles to get back to zero. The range showed one and the motor was still running at the pump.
That being said it's not my preference to run it close but when needed you have to know if the computer is telling the truth to rely on it. I intend to tow my boat to the lake and back each trip. Currently I can make it on one tank in my old truck. I have no idea if the F-150 will do it. It's one stop I don't have to make if it will. It's not a big deal if it won't but if it's close I want to know so I can make the decision where to stop.
I don't know how Ford programmed their computer but I suspect the range is not calculated from the economy figure. They publish that the average distance for DTE is 500 miles. That should be a running average. There is no reset for that as it is taking the last 500 miles consumption and multiplying the fuel remaining to get the range. Anyway that's how I do it EXCEPT not for 500 miles! It needs to be more like 40 miles to allow changes in consumption to filter into the calculation. That will give you an update much sooner.
In my testing on the motorcycle I ran the tank empty several times. As for overheating the pump motor, it cannot run out of fuel because when the pressure drops the engine falters and quits which powers off the pump. Never had a problem. I can't say what the Ford will do but I will find out and let you know.
My experience with fuel tank capacity has been that the manufacturer states the WHOLE volume of the tank. The usable volume is the whole volume minus the pump and other parts inside, minus the volume below the pickup tube. My Chevrolet Duramax had a stated volume of 36 gallons. Actual is 34. That can only be determined by running it empty then measuring the fill-up volume. I will do the same on the F-150.
If Ford is using the gauge float for measuring it can't be accurate. If they are using the injectors for measuring it can be accurate. If they are actually averaging over 500 miles the average is not useful. My computer was user selectable from 1 mile to .... can't remember the limit but much higher than is useful.
I have not emptied the first tank yet and it will be awhile if this weather keeps me off the road.
I have a couple of questions. The computer stores normal history and towing history. How does it tell there is a trailer? Do I need to select which history to use in the settings when I am towing? The manual does not explain. See page 124, DTE calculation.
Thanks for all your input.
03-03-2014, 07:47 AM
#40
Senior Member
My truck notifies me of low fuel around 60 miles to empty, that's usually when I fill up. I only use no ethanol gas. Luckily I live in a town that has 5 ConocoPhillips stations. When I fill up at 60 miles to empty, my "A Trip" says I've used around 32 gallons. I've always been taught to reset the "trip" after every fill up and pick a number to refill the tank every time. Typically, I fill up at 600 miles.
To answer whether or not I think the DTE is accurate. Possibly so, but I'll never test it. I think it's a good gauge. I'm only 27, but call me old fashion. I believe in calculating my MPG by hand every tank, and filling up based on the amount of miles I've put on a tank, not what a gauge or computer is telling me.
To answer whether or not I think the DTE is accurate. Possibly so, but I'll never test it. I think it's a good gauge. I'm only 27, but call me old fashion. I believe in calculating my MPG by hand every tank, and filling up based on the amount of miles I've put on a tank, not what a gauge or computer is telling me.
