I noticed recently that my '17 F150 (3.5 EB, 10 speed, start/stop) has been getting worse-than-expected MPG, according to the display--it says I'm getting 14.2 MPG average.

I don't really use my truck for anything but my commute to work, which is about 4 miles round-trip. It's not city driving, but there are several traffic lights along the 45 mph highway I take, but the long stops shouldn't make much difference with auto start/stop. I've been taking it easy on takeoffs from stoplights lately (in a mostly failed attempt to boost my MPG) but always end up flooring it once to get onto the highway.

From what I've read on here lately, this doesn't seem right. Should I try to hand calculate?

MPG doesn't matter that much to me, but I can't help but notice that my 3.5L is supposedly getting slightly better MPG than either of my parents' 6.2L Raptors!

 

For that short of a drive with stop and go plus a bit of the loud pedal on the highway section, that sounds right to me.

I have an 11 mile commute, about 8 of it freeway. I am holding on to about 18.5 on the LOM with grandfatherly driving for the most part. 2.7 btw.

My Taco 2.7 was getting 18.9 doing this run.

 

Yes, you should hand-calculate. What most of us have found is that the actual MPG when hand-calculated over at least three tanks is from 5 to 10% less that what the truck shows, which is why I call it the Lie-o-Meter.

But yours may be quite different. So I would encourage you to hand-calc for several tanks and find out what you are really getting. And for comparison purposes, I get about 17 MPG in the conditions in which you are driving, but I don't floor it or even accelerate hard. I drive like the grandpa I am - until I don't.

 

My typical commute is ~~ 35 miles. I start at a 2500' elevation, and go down to basically sea level, then reverse to go home. We have a long driveway (~~ .8 miles), which I drive at ~~ 10 MPH. The majority of the drive has no stops, and I vary between 30 MPH, and maybe 60 MPH depending on traffic. At the tail-end on the way in, there is "usually" a lot of traffic, and maybe about 4 stop lights (about the last 4 miles).

My MPG varies between ~~ 18 and ~~ 21 according to the LoM. The hand calculated MPG is almost always exactly 1 MPG worse than the LoM.

When I am not commuting, trips to town are similar with town driving on the downhill side, and relatively slow country driving on the home side (mountain roads have a lot of tight curves too). Mileage on these trips are similar to my "commute" trips.

When we pull our TT, it's a whole different world, and I don't have consistent numbers, but it's a lot worse than when I'm driving alone or even with 1-3 passengers. However, the MPG numbers look mostly like 12-14 MPG. Again, depending.

 

That's really all it takes, especially on your short drive. I make a game out of seeing how high up I can get the displayed MPG on the display sometimes. Being a featherfoot on the pedal for 20 miles of flat ground might get the display up 0.3. Having to accelerate up a hill or to get on a freeway, where the turbos kick in, will drop the displayed MPG easily twice that*. A few seconds of leadfoot will always trump an hour of careful driving.

*Obviously this depends on how long your trip meter has been running. If you have 2000 miles on it and it's showing 20.0MPG, you might not even see a change to the display for a single leadfoot maneuver. If you recently reset it, you might see that freeway merge drop it down 3-4MPG. Also I'm basing this on the available display in the 301A XLT. The higher end models may have other options for measuring MPG. In the end, hand calculating is the only way to be sure.

 

I uploaded the data from my Fuelio app, and did a couple of quick checks.

Background: I have been tracking my fuel usage since the truck was new, and I have about 26,000 miles on it now.

At first I only tracked it manually, and after about 4-5 thousand miles, I manually entered the early data into Fuelio. Also, for about the first 10,000 miles I did not enter the console readings.

None-the-less, I think it is a pretty accurate reflection of my mileage over the last 2+ years with our 3.5L EB. It's interesting (at least to me) that the average and minimum are about 1 MPG different between the hand-calculated and console. However, the maximum is only 0.3 MPG different.

Here's the data hand calculated:

AVERAGE = 18.2
MAXIMUM = 20.7
MINIMUM = 15.4

Here's the data from the console:

AVERAGE = 19.3
MAXIMUM = 21.0
MINIMUM = 16.4

 

You will need to make sure you are using your meter correctly first. First thing you need to do is go fill your gas tank. Then, reset the gas mileage meter in the dash, run the tank down to 1/4 or so, refill and reset. This method WILL get you within .1mpg of the hand calculation. This is the only way to get the meter to be accurate.

 

that does not sound that far off. our 2014 edge with the 3.5 only gets 16.5

 

Thanks guys! I'll do a calculation the next time I fill my tank and use that up. Since I have a 36 gallon tank and travel 20 miles per week, it's gonna be awhile...

I have noticed how much recent trip reset will affect my average MPG. Once I noticed that the estimation dropped from 14.5 to 13.9 in a couple seconds, just by making that turn onto the highway. I had a car barreling down on me at 55, I had to let my engine do what it does best...

 

The computer calculates mileage over the last 1,000 miles, or since the last reset if it is less than 1,000 miles. If your hand calculations are not done over the same miles you won't be comparing apples to apples.

 

20 miles a week?!? I only work 2 days a week, and I do > 200 miles per week! That low a number could be part of the issue. It implies that you're doing really short trips, and a lot of your mileage is doing just warm up.

 

AND consider using e-free fuel. No, I am not a seller of that stuff but with a 36 gal tank, I am sure you will be over 6 months before you need to buy gas and I am not sure the e85 stuff will retain all your engine needs for that time.


YMMV

 

the problem with ethanol free gas is it is hard to find.
some states do not sell it at all.

 

This. Only one station in rural northern Nevada carries it that I know of, and they just added that pump recently. I've already ruined one lawnmower using the ethanol gasoline!

 

That might be true, however 36 gallons of 10% ethanol gas in the tank for 6 months or more insures the engine will be forced (at some point) to operate on fuel below specifications of the factory. Alcohol is used to increase the octane rating which is a measure of the resistance to knock. I do not know how well the computer systems will be able to deal with the last few gallons of that tank at 20 miles a week.



Try here:


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Or here:


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