Your fuel economy is 30.0 MPG (7.84 L/100km, 12.75 km/L).
30.0 MPG equals 7.84 L/100km. For context, the average new US passenger car achieves about 28 MPG combined.
To get the most accurate reading: fill the tank completely, reset the trip counter, drive at least 100 miles, then fill again and use the exact gallons pumped.
US and UK gallons are different units. A UK gallon is 4.546 L vs 3.785 L for a US gallon, so the same car shows a higher number in UK MPG.
Speed is the biggest single lever: aerodynamic drag grows with the square of speed, so dropping from 75 mph to 65 mph often improves MPG by 10-15%.
Next stepTrack three or four consecutive fill-ups and average them for a reliable baseline that smooths out variation in driving style and terrain.