2017 F150 3.5 Eco - trip computer MPG 10% high

[Njg]

Originally Posted by TCwheels

I'm surprised at how poor that MPG is from the ecoboost 3.5. My Triton 5.4 gets 14-15 towing.

Ethanol-containing gas? Premium or regular?

[jcl]

Originally Posted by TCwheels

I'm surprised at how poor that MPG is from the ecoboost 3.5. My Triton 5.4 gets 14-15 towing.

My 5.4 Triton in an Expedition made 230 hp. Later 5.4 models made 260 hp. The Ecoboost 3.5 makes 365 hp. If you drive an Ecoboost to take advantage of that higher HP, you have to pay to play.

[Dave-n-Janet]

TCWheels: By calculation or computer? LOL
My trip did include a good bit of winding up and downs. Used regular and all fill-up pumps were marked 'May contain up to 10% Ethanol'. I know when stations started changing over my RAV4 mileage appeared to drop 5-6% when using the 10% Ethanol, but with such low oil prices not sure refiners are still putting in 10% corn juice.

Definitely when you give it the gas you can watch the instantaneous MPG drop WAY down...

[TCwheels]

Originally Posted by Njg

Ethanol-containing gas? Premium or regular?

10% regular

[TCwheels]

Originally Posted by jcl

My 5.4 Triton in an Expedition made 230 hp. Later 5.4 models made 260 hp. The Ecoboost 3.5 makes 365 hp. If you drive an Ecoboost to take advantage of that higher HP, you have to pay to play.

Good point!

[TCwheels]

Originally Posted by Dave-n-Janet

TCWheels: By calculation or computer? LOL
My trip did include a good bit of winding up and downs. Used regular and all fill-up pumps were marked 'May contain up to 10% Ethanol'. I know when stations started changing over my RAV4 mileage appeared to drop 5-6% when using the 10% Ethanol, but with such low oil prices not sure refiners are still putting in 10% corn juice.

Definitely when you give it the gas you can watch the instantaneous MPG drop WAY down...

Old school calculated!

I've only owned the truck since just about everything went to 10%.

I agree about the instant MPG! I turned that display off right away, it was making me crazy and I was making my wife crazy with my constant commentary!

[slowmover]

Originally Posted by TCwheels

Old school calculated!

I've only owned the truck since just about everything went to 10%.

I agree about the instant MPG! I turned that display off right away, it was making me crazy and I was making my wife crazy with my constant commentary!

As with others noting the effects of winds and traffic etc on instant mpg, it's also a way of testing for best fuel economy per WD adjustments. When WD isn't ideal, mpg will be down.

I've taken my TT to the first truckstop with Scale thirty miles from an uneven campsite (extended stay), and looked at instant mpg before and after using scale to re-set WD and seen well over 10% difference once done.

Of course this assumes one already has some familiarity with scales, setting WD by numbers, and an interest in best performance. Setting a hitch by fender measurements is crude. This use of scale and checking mpg, isn't.

I already know what to expect as to average mpg, so by getting WD and TV tire pressure to spec by Scale measurement, I've lessened rolling AND aero resistance to the lowest point.

The overhead will also show the improvement made by using a VPP hitch when when tested on a road course earlier used to check the previous set-up.

On older threads we've discussed this in re setting travel speed. Some days the winds are advantageous. Other days call for a reduction in speed (as higher fuel burn correlates to more difficult rig handling with crosswinds. Safety, not just some dollars for fuel).

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[Mollysdad]

90% of auto makers have a built in error in their speedometers and odometers. It's a fudge factor so the auto maker doesn't get sued in a "speeding ticket" class action suit. Your speedometer always reads high, by design. Compare it to a GPS to get the real speed.

[jcl]

Many speedometers are designed to read high. Odometers are designed to read accurately.

The NA (SAE) standard is for a range that is +/-.

The Euro standard is for -0, but +10% of true plus 4 kph. Manufacturing tolerances mean that manufacturers aim high to avoid under reading in the real world.

But only on speed, not distance.

[slowmover]

GPS isn't perfect either.

63.5 mph will show as 64.

Odometer and engine hour meter are what count as to maintenance, thus to looking at fuel burn.

Average MPH for a given fuel burn is the real secret.

It still is a matter of X distance over Y time.

One may "think" 66-mph is "faster" than 62-mph, but the proof is the difference in the average. There may be little to no difference given traffic, construction, terrain and weather.

Test it and see.

But there'll be no doubt as to which returns a lower fuel burn rate.

.

[Scorge-ION]

GPS makes a position measurement once a second (usually) with a typical 15' error (my Galaxy is typically 150') so you can stand stationary and move as much as 30' in a second. Don't trust GPS for speed. GPS is kinda-OK in a vehicle but it badly overestimates distance traveled at walking speeds. Sure, they average errors out using a Kalman filter, of what order, I don't know.
Ford diesel pickup automatic mpg estimation, I don't know what they measure to get it but it's too variable. Case in point, I had to borrow a work truck this last week, F-350. When I left, the mpg displayed 13.4 and I doubt the guys who ordinarily drive it have reset it in 40,000 miles. I drove about 170 miles, 30 miles of it in 4WD. I drove up and down the mountain in low range. When I got back, the mpg displayed 13.5 mpg. We don't usually check the fuel mileage ourselves, the Gas Boy reports that to the motor pool mechanic. However, the kind of driving I was doing should not have increased the long term average.

[DKB_SATX]

I have found that the trip computer MPG in most vehicles I've owned or rented is somewhat optimistic. On my '17 F150 it runs around 1 mpg higher than the hand-calculated MPG when I fill up. So, when towing (getting 10-11 mpg towing the 26U around 68ish mph) it's about 10% off. When I'm not towing (getting around 19-21 mpg running 75ish) it's about 5% off.

So, I don't particularly drive for fuel economy. I'm getting easily 15% better MPG towing than I got with my '07 F150 5.4-liter (towing a much lighter trailer that was narrower.) At the same time I find it MUCH easier to maintain that pace than I did with the older truck, with plenty of power in reserve when I want or need it. I get well over 20% better MPG not towing than I did with the '07.

It appears to me that the truck just ignores idle time. I doubt that's enough to account for the full discrepancy between the calculated and trip-computer mileage, but it's part of it. In Texas summers I idle the truck a fair amount since I travel with my dog and I've been paying attention to the MPG indication... it should definitely drop when the truck is sitting there idling, especially shortly after a fillup and it simply doesn't budge when the truck is running but isn't rolling.

[jcl]

My memory was jogged by the Car and Driver link above. BMW models have (had?) a fuel consumption correction factor in the on board computer. It was adjustable from 750 to 1250, and was defaulted to 1000. It gave the ability to adjust the display mpg up or down by 25%, essentially a correction factor. It was in an engineering menu, but accessible by owners using a series of buttons on the dash. Not in the owners manual, but documented on line. I had done it on a vehicle about four cars back, but not on any vehicle since, since the l/100 km display reading was pretty good on each of those vehicles.

Reading online, someone purchased a used BMW vehicle with the display showing 40 mpg, and didn't see that after he purchased the vehicle and measured his fuel consumption. Turned out the adjustment factor had been set to 750, so it was reading 25% optimistic.

Searching on line now shows that VW, Audi, Subaru, and BMW have this feature, but most require a dealer service tool to adjust it. Interesting that other manufacturers don't appear to support this, but perhaps any dealer techs reading could advise if any other manufacturers do.

Correction is generally going to be required for best accuracy, considering winter fuels vs summer fuels, ethanol content and resulting fuel energy content, and so on.

[DRPREECE]

Originally Posted by PatLee

I use to track my MPGs with vehicles and then one day, I had a talk with myself: "So, what are you doing here besides wasting precious time? What changes with doing this? When the vehicle is low on gas, you're still going to fill it up, right?" From that day forth, I threw out the spreadsheet and felt like I had gotten rid of an irksome task.

Exactly! While it may be interesting, what is the outcome? MPG is impacted by too many environment variables you have no control of or means to adequately measure.

Unless I see large or sudden changes from average values, I'm not concerned.

As an FYI - my 2017 F250 diesel has a setting buried in the computer to change the mileage calculation used when towing. It is a setting that is not automatically toggled when you activate the Tow/Haul mode and it remains set until you change it back. Not sure exactly what the differences are, but I think it is less optimistic on the Miles to Empty projection. I have never checked either setting against manual calculations.

Not sure if your TV has a similar setting.

[rodsterinfl]

What really burns me is my neighbors 2013 F-150 with the same engine pulling brand "x big box trailer with two slides" that weighs only 200 pounds empty weight less than my 30' FC and he gets 17 mpg calculated.

My computer is off as well but I do not believe your neighbor is getting 17 towing. No way. He is probably reading his computer. I have seen up to a 2mpg discrepancy but mostly 1-1.5mpg difference. I never go by the vehicle computers anymore. I will share that I was able to raise my mileage by avoiding lugging as much as possible. It seems the ecoboost is very sensitive to moving accelerators. Try getting up to speed more quickly and then cruising. I get at least 1 mpg more doing that- in town about 2mpg more.

My opinion on the ecoboost is that it is getting superior torque/power at low RPM as a primary feature with smaller engine and lighter weight as a secondary providing better mpg. Towing is not really that different. I know from monitoring this and other forums for at least five years, diesels get about 14mpg and gassers get about 12mpg - on average, period. When someone says they get way over that I question their math. Often I believe, they are reading their computer. My ecoboost has stated that I got 15mpg pulling once. I did get good mileage that time but not 15mpg. I was behind a semi for miles. Also, I found, by digging, that MOST travelers run 60mph average. Speed, grade, wind, all play a part. I get 12mpg average but overall I notice better mileage on state roads versus interstates, most likely due to lower speeds. The lugging tip is valid though. I have noticed it as it is my daily driver as well. Drive it on Fuel Economy screen and change one of your gauges to turbo boost to monitor it all.

[KAYAKAMPERS]

Just back from a 4400 mile trip pulling our 26' Overlander and recorded a 13.8 MPG from our 2016 F150. We are pretty happy with choosing the 5.0 V8 Coyote motor. Simple and basic ( as simple as you can get these days ) and much better than our Dodge Dakota 4.7 V8 we had previously.
Given the complexity of newer drivetrains these days, they are still superior to what was just a few years ago new technology. I had a 1989 F250 with a 351 Windsor and a truck camper on the bed. I was lucky to get 6 MPG!

[GettinAway]

I quit tracking MPGs down to the tenth gal several years ago also. What I do do is push the trip one odometer to reset it at every fill up. I'll ballpark it when I fill up next time and hit the reset. The only time I ever had a big discrepancy was when I had taken an old Chevy Blazer in to the vo-tech high school for a tune up. The kids didn't get all the spark plug wires hooked back up.
I buy used vehicles, and usually get base models. I don't have one that'll give me a mpg reading. Well, my motorcycle does give me an mpg reading, but I still hit the odometer button on filing up.

[RedSHED]

I've read elsewhere that the trip computer FE employs a first order filter. Basically, data becomes less important for the calculation with every mile. I did an experiment on a trip once, resetting trip A with every fill up and not touching trip B after we left the driveway. Somewhere just before the second fill up, I compared the two and they were the same.

Also, my nonFord truck displays a little high. We're pulling a 16', and seem to average (pencil and paper) 13.5 towing (~11000 miles so far) with a best of 15.5 or a little better.

[rodsterinfl]

I am out on my first leg of the journey with almost 500 miles. This time I set the trip computer on towing calculation (never did that before). The computer mileage matched my calculated mileage for the first time!
My 2009 V8 F150 computer and this one were usually high on MPG. This is the first time I have gotten accurate readings. I will check it on the route home as well.

[TCwheels]

I'm getting calculated 15.1 towing my FC20 with the 2009 f150 platinum with the 5.4 Triton V8. No 70mph expressway driving. 60mph Blue Highway driving.

I'm considering changing my current search for a 2015 or 2016 f150 platinum or king ranch to the 5.0 V8.

It doesn't look like I'll be able to get the kind of towing MPG I'm currently getting if I go with the Ecoboost - based on what I'm reading here...