Maverick mileage versus my calculations

[Pete Sheppard]

WOO-HOO! 41.7mpg at the pump, with the truck calculating 44 since last fillup!!!
This was after a trip from Birmingham, AL to Norcross, GA--a NE suburb of Atlanta-- and back, cruising at 60 along relatively flat I-20, then crawling through the Belly of the Beast (Downtown Corridor through downtown ATL at rush hour).
Now that I am getting a good feel for my Mav's fuel performance, I'll stop with repeated trip reports.

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[AutobahnSHO]

 

[AutobahnSHO]

Although changing the tire size may correct the mpg discrepancy on its own

If you go up in tire size, the computer will think you're going further on the same amount of gasoline, so it will be more "off".

 

[MaverickDragon]

If you go up in tire size, the computer will think you're going further on the same amount of gasoline, so it will be more "off".

Actually, the car's software doesn't know the tire circumference. It measures rotations rather than actual distance travelled, so a larger tire will travel a greater distance on each rotation than the stock sized tire.

The odometer will be showing less distance than is actually travelled, assuming that it was accurate in the first place, so the tire size increase won't change the difference in your calculation of mpg's vs. the car's reported mpg estimate, as an owners calculation uses the miles on the odometer for the dividend. ( Miles / Fuel )

It will appear that you calculated mpg as well as the car's will go down though, because you are actually travelling more miles than your odometer incorrectly states with a larger tire.

Another change with a larger tire is that the speedometer will be displaying less speed than the truck is actually traveling, for the same reason.

I know there is an engineering option to change the estimated mpg figure via the cars computer, but maybe someone who knows can mention if a similar feature exists to calibrate the speedometer / odometer based on a change in tire size.

This calculator will let you see the difference in speedometer error.

 

[Bguy]

When I shut off the truck from a drive, the display shows miles driven and below that electric miles driven. Are you saying if I take a certain number of these trips after resetting my trip meter the miles displayed on the trip meter will be the sum of the total miles per trip minus the electric miles per trip?

I'm using the trip one display not the turn off car display and thats were i noticed that if I added the two numbers then my hand calculation came close to the car mpg.
I'm certainly happy with the fuel economy with my awd hybrid just wish it was a PHEV like my CMAX ENERGI. With my cmax I've gotten as high as 998 miles to a fill up of slightly less than ten gallons I think it was. But i plugged it in every night and made lots of short trips so the gas engine wasn't running much. At night the electric rates are low so makes for very economical driving. Only takes about 8 hours to charge up on 115vac.

 

[KrS]

I have to set my AFE bias to 935 for it to be remotely accurate.
965 in the summer.

 

[HeyBales]

I noticed the discrepancy also but then discovered i was using the trip meter which splits off the electric miles from the gas miles. When i added the two together the computer mileage came much closer to my hand calculated mileage. Next time I will use the odometer mileage and not the trip meter.

Are you sure that doesn't say total, and then the amount that are electric?

 

[HeyBales]

When I shut off the truck from a drive, the display shows miles driven and below that electric miles driven. Are you saying if I take a certain number of these trips after resetting my trip meter the miles displayed on the trip meter will be the sum of the total miles per trip minus the electric miles per trip?

No - you are reading the display correctly.

 

[Bguy]

Are you sure that doesn't say total, and then the amount that are electric?

chuckle...didn't notice I just noticed the numbers came closer to matching when i added the two together

 

[Timothyd]

You adjust the setting using engineering test mode. There's a bunch of threads on it.

When people post their mpg's they are unknowingly incorrect, I used to mention this but have since given up lol. Generally about 5% high.

I'm in the 40s either way. Not going to get twisted about it.

 

[inline_five]

This!

All my Toyota's were "optimistic" too. The Prius v I traded in for my hybrid Maverick was optimistic by 2 mpg. My Maverick was also optimistic by a couple mpg. What I appreciate about the Ford is that I can adjust the indicated mpg via the engineering test mode. Now it's close enough to trust (i.e., when I hand calculate sometimes it's a bit high, sometimes a bit low, but usually within an expected margin of error). I could not do that with my Toyota's.

Therefore, go into the engineering test mode and adjust it. It's easy, and then your indicated mpg will be reasonably accurate!

My 3rd gen Prius is off by 2-3 mpg as well, I noticed my speedometer is 2 mph high at highway speed so this may account for some of it. It thinks I'm driving further than I actually am by almost 3%.

 

[Phimosis]

Don't holler folks. I looked and did not see this on the forum addressing this particular subject. My 2025 Mav indicates that I'm averaging 38.6 mpg. However when I calculate my own mileage I consistently come up 5 mpg less.
Any ideas why?

This is normal. All manufacturers do this. The likely answer is that they did focus groups and the focus groups reported that the majority of people, were the most satisfied with the vehicle, when the the “lie-o-meter” was overstating the MPG, and were the least happy with it, when it was understating the actual mpg.

As mentioned above, you can reprogram the “AFE bias” to be accurate, if you so choose.

 

[KenE]

This!

All my Toyota's were "optimistic" too. The Prius v I traded in for my hybrid Maverick was optimistic by 2 mpg. My Maverick was also optimistic by a couple mpg. What I appreciate about the Ford is that I can adjust the indicated mpg via the engineering test mode. Now it's close enough to trust (i.e., when I hand calculate sometimes it's a bit high, sometimes a bit low, but usually within an expected margin of error). I could not do that with my Toyota's.

Therefore, go into the engineering test mode and adjust it. It's easy, and then your indicated mpg will be reasonably accurate!

And for those owning other, likely older Ford vehicles, Engineering Test Mode (ETM) has existed at least since 2016 F-150, perhaps longer. Ive used ETM several times on various Ford vehicles to achieve closer displayed MPG.

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