Peugeot 208 2015 1.2 PureTech Fuel Consumption

Hello. I'm having fuel consumption problems with my new 2015 model 208. I wanted to get your opinions. I researched real-world fuel consumption, which is 6 liters in the city. However, my car currently consumes an average of 10 liters. I've added oil and checked the tires. I'm not very knowledgeable about cars, so what could be causing this? What would be helpful to check?