Convert Imperial Gallons per 100 Miles to Miles per Imperial Gallon

Convert Imperial Gallons per 100 Miles (Imp gal/100mi) to Miles per Imperial Gallon (mpg (Imp)) instantly and accurately.

Conversion Formula

mpg (Imp) = 100 ÷ Imp gal/100mi

About Imperial Gallons per 100 Miles

Imperial gallons per 100 miles is the British volumetric consumption equivalent using the Imperial gallon (4.54609 L). Since the Imperial gallon is ~20.1% larger than the US gallon, a vehicle's Imp gal/100mi is correspondingly smaller than its US gal/100mi. A car at 7 L/100km needs 2.977 US gal/100mi but only 2.478 Imp gal/100mi. The unit appears in UK fleet management software and automotive engineering reports. A 50 mpg(Imp) car uses 2 Imp gal/100mi = 5.650 L/100km. 1 Imp gal/100mi = 4.54609/1.609344 = 2.8248 L/100km.

About Miles per Imperial Gallon

Miles per Imperial gallon (mpg(Imp)) is the UK and historically Commonwealth standard. The Imperial gallon (4.54609 L) is ~20.1% larger than the US gallon, so mpg(Imp) is always numerically higher: a 7 L/100km car achieves 33.6 mpg(US) but 40.4 mpg(Imp). All UK VCA-certified specs list mpg(Imp). Typical WLTP combined: supermini 45-60 mpg; full hybrid 55-75 mpg; diesel family car 48-68 mpg; large petrol SUV 28-38 mpg. 1 mpg(Imp) = 1.609344/4.54609 km/L = 0.354006 km/L; L/100km = 282.481/mpg(Imp).

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