GTSSportCoupe
2LTE abuser
I once got into a similar discussion with another Ford Escape Hybrid owner (yes, I owned one). He claimed 40+ mpg. I routinely got a bit under 30, maxed out at 35 or so for one tank. Difference was I was meticulous about record keeping, he wasn't (I have all tanks recorded in an Excel spreadsheet for reference). So a tank where he under-filled became his 'record' and then became his average. So to even the playing field I had one portion of my route where I was mostly coasting, and recorded 55 mpg over the length of the mileage display and too a photo.
But his case was mornings going 30 miles downhill to work with no wind, and 30 miles going back up that hill with a 25 mph tailwind (SoCal where they place the wind turbine farms)... and he finally acknowledged he never exceeded 50 mph. No doubt he got good mileage, but I doubt the real number was anywhere near his claim (again, he wasn't keeping good records).
As for a TDI Jetta routinely getting 55? Even the guys with bragging rights that reported it to fueleconomy.gov average around 47 -- which by the way is pretty darned good -- though good records are not required to post there. But again, these are hardcore mileage people who do everything they can to get top mileage so they can report the same.
-- See https://www.fueleconomy.gov/mpg/MPG.do?action=mpgData&vehicleID=14269&browser=true&details=on
Then there is the case of my motorcycle that always got better mileage than most everyone else, nearly 55 mpg for an ST1300A - everyone else claimed only mid 40's mpg. My speedometer was also 10% or more fast, though I was never able to actually prove the ODO was off by that much, so chances are my claim there is smoke and mirrors -- but I do have good records. Point being I don't even believe my own claim for the ST1300A because I know there are reasons for doubting it.
Here's samples of how I keep track of my mileage.
ST1300A
Date - Trip - Miles - Gallons - Cost - Per Gallon - Mileage - Est. Miles
08/12/10 131.1 17,410.0 2.39 8.61 3.60 54.81 131.0 0.1
08/12/10 153.3 17,564.0 2.91 9.60 3.30 52.66 154.0 (0.7)
08/13/10 122.1 17,686.0 2.64 8.81 3.34 46.25 122.0 0.1
08/13/10 103.4 17,789.0 1.85 7.95 4.30 55.89 103.0 0.4
08/14/10 199.2 17,989.0 3.46 13.41 3.88 57.59 200.0 (0.8)
And estimated miles is [Miles - prior Miles] to check for missing Trip receipts ...
FJ Cruiser
Date - Trip - Miles - Gallons - Cost - Per Gallon - Mileage - Est. Miles
04/10/12 332 - - 331.9 - (first tank I filled)
04/15/12 271.1 603 15.03 59.81 3.98 18.03 271.1 -
04/25/12 279.7 884 15.99 67.80 4.24 17.49 281.0 (1.3)
05/02/12 293.2 1,177 16.35 63.43 3.88 17.93 293.0 0.2
05/11/12 308.0 1,485 16.22 68.10 4.20 18.99 308.0 -
05/21/12 292.8 1,778 15.84 65.38 4.13 18.49 293.0 (0.2)
06/06/12 258.7 2,037 16.09 64.35 4.00 16.08 259.0 (0.3)
06/14/12 331.9 2,369 16.04 63.33 3.95 20.70 332.0 (0.1)
06/19/12 109.5 2,478 6.37 25.46 4.00 17.20 109.0 0.5
06/20/12 329.2 2,807 16.64 66.21 3.98 19.78 329.0 0.2
...
12/18/14 236.8 21,683 14.51 38.74 2.67 16.32 237.0 (0.2)
01/01/15 214.8 21,898 12.93 36.18 2.80 16.61 215.0 (0.2)
01/03/15 266.6 22,164 14.99 35.95 2.40 17.79 266.0 0.6
02/11/15 256.1 22,421 15.62 35.90 2.30 16.40 257.0 (0.9)
02/28/15 265.3 22,686 14.84 41.52 2.80 17.88 265.0 0.3
03/22/15 284.8 22,971 15.31 45.54 2.98 18.61 285.0 (0.2)
In all this, the only thing I question is the data and how it was obtained. The average person does not keep a diary of fuel use, let alone an accurate one, yet they will make claims of exceptional mileage: all based on too little real data. On the flip side I have also heard people report 175 mph and 10 second quarters for their Harley flat head because they raced and beat a Dodge Viper on the street. No doubt the Viper was obeying the speed signs.
Again -- I trust your 60 mpg claim is sincere and that you believe it; but I doubt it is based on good science.
I suspect you are confusing Imperial and US gallons? His 57 Imp mpg = 47 US mpg.
Anyhow, this is way off topic for this thread, so lets leave it at that.