With about 1300 total miles on my 2024 x1 28i I just completed my 1st long drive. The 345 miles were mostly highway diving between 55-68 mph. After filling up with 9.317 gallons
I calculated the actual MPG to be 37.03 on the 345 trip. 
The X1 stated (calculated) 40.1, so I’m guessing it’s a bit more optimistic than the true #.
Either way I’m impressed with the mileage as it’s way above the mfr.’s 28 overall or 34 highway mileage published claims. Impressive #’s for a 241 hp engine with an automatic transmission.
