FordService

No problem, exrub. I’ll get back to you as soon as possible.

Deysha

SennaF1

I think the OP's question has been answered pretty soundly. I will say that my "miles to empty" estimate is consistently over-optimistic. In reality, the reading seems to drop @ ~2X the actual miles I've driven. For example, if I go take a 5-mile city driving trip, it'll drop 10 miles off the "miles to empty" display reading. The only time it's close to accurate is when I'm highway cruising. It's as though it calculates the figure based on getting the 5.0's 26-mpg highway figure at all times.

Not sure if it's a quirk of the fact that ~90% of my driving is city traffic, or it's stuck using some sort of factory default value for the calculation instead of my actual avg mpg. In any case, this is the first car I've owned that even has a countdown in addition to the good old fuel gauge, so I just shrug and move on with my life.

tukatz

I refueled recently when the Miles to Empty number was quite low - I don't recall exactly what it was. I pumped in 14.273 gallons, so I'm guessing that what the manual call indicated capacity must be between 14.5 and 15 gallons and the empty reserve must be 1 to 1.5 gallons.

My gallons used display read 14.7, but that number is always somewhat higher than the amount I can pump in, and the difference increases as the gallons used gets higher.

I suspect the Miles to Empty calculation must be based on 15 gallons. I'll try to remember to take some notes when I hit the road in a few days. I'll be getting on the freeway with only a few miles on the tank and will stay on it until I refuel at a little over 300 miles.

tukatz

I made my round-trip drive to Grants Pass today. I had filled the tank and had 2.5 miles when I left home. I was sort of cooking along through Washington, but realized that I was making very good time (I left home a few minutes after 6:00) and could ease off and let the mileage climb. The Miles to Empty was looking a bit pessimistic before I stopped at a rest area about 150 miles into the trip. When I restarted the car the MTE had jumped a fair bit. I refueled near my sister's home with 375.6 miles on the tank. My displays indicated I had used 12.8 gallons (although it only took 12.572 - normal) and had averaged 29.2 MPG. The MTE was consistent with it being based on 15 gallons. When I reset the trip meter the MTE displayed as 432 miles - very close to 29.2 times 15. My actual MPG calculated out to 29.875. I ran in the upper 60s to low 70s for most of the trip down.

Bucko

Even if there's any factual truth to having one or two gallons left when the guage shows "E", I simply don't run the engine past 2 to 3 miles when the "50 miles to empty" comes on. I always try to make it a point to fill up when the guage reads 1/4.

tukatz

I have just confirmed for myself that the MTE calculation is based on an average of the last 500 miles (as was suggested earlier in this thread) and 15 available gallons.

My fill up this morning was with 7 Miles to Empty after driving 379.5 miles with a displayed average MPG of 25.6. Those miles represent 75.9% of 500 and the result of dividing 379.5 by 25.6 is 14.82 gallons assumed used.

My fill up yesterday was after driving 375.6 miles with a displayed average MPG of 29.2. If you subtract 379.5 from 500 you get 120.5 miles. Divide 29.2 into 120.5 and you get 4.13 gallons assumed used.

Add 4.13 to 14.82 and you get 18.95 gallons assumed used for the total 500 miles. Divide 18.95 into 500 and you get 26.385 average miles per gallon. Multiply 26.385 by 15 gallons available and you get 396 miles to empty. After this mornings fill up Mile to Empty displayed as 395.

So there you have it.

2012GT

My mpg gauge is very accurate. I don't even manually calculate anymore.

tukatz

Mine tends to be a little low, while my gallons used is a little high. My fill up yesterday was with 29.2 MPG and 12.8 gallons used displayed. The actual number were 12.572 gallons pumped in and an average of 29.875. The displayed numbers are close enough.

2012GT

that's fine

Xar

tukatz - next time you go to GP let me know, I'd love to check out your ride

dreday23

Yea mine changed all the time. I put 93 in it without a tune and it said 295 until empty. I ended up going exactly 300 miles before i refueled with it saying 47 miles to empty. after refueling it adjusted itself to say 340 miles to empty. this was with using 93 from the same shell station

tukatz

D...! I just made another one day round trip yesterday. Got almost 32 MPG on the way down. Will be down there again 8/20. PM me to see if we can get together.