Conversion of 59 MPG (USA) in L 100km (liters/litres per 100 km) is 4 liters per 100km. Cars that get 59 mpg in USA would consume 4 liters of petrol if it was driven for 100 km in Europe.
If in the UK and you are asking how many litres per 100 km would be consumed for a 59 mpg car (UK) in imperial measure, then we would convert 10 UK mpg as 4.8 litres per 100km. This means that a 59 mpg car in the UK would consume 4.8 litres of petrol if driven for 100 km.
Just to clarify:
59 MPG (USA) = 4 L in 100km
59 MPG (UK) = 4.8 L in 100km
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