The Rolls Royce Cullinan mileage stands at 6.2kpl for the base model. The average of Rolls Royce remains under 10kpl thanks to its large V12 petrol engine that has a displacement of 6.75 liters. The Rolls Royce average per liter is lower than the Bentley Bentayga and also other luxury SUVs. Our range and fuel cost calculator will help you decide optimum costs for your next trip and also will give you a ballpark figure of the fuel economy range you can expect from your SUV.