11 miles per liter is under 44 mpg, not 50. :-)
Just to clarify the confusion Curtis, US gallons are not the same as Imperial/UK gallons. A US gallon is smaller. It's 83% of the Imperial gallon.
Robin is correct that 11 miles to the litre is 50mpg, on this side of the Atlantic.
All of our pumps are only showing litres for dispensing fuel so we tend to think in terms of the miles we get for a litre. 10 to 11 miles/litre is about average for most big engined bikes and petrol engined cars under 1.5 litres, but this can vary depending on traffic conditions etc.