Official fuel efficiency figures for the Sonet, including the Anniversary Edition variants have been provided by Kia. Claimed efficiency for the 1.0-litre turbo petrol engine is around 18.3-18.6 km/l, while the 1.5-litre diesel engine claims about 19-22 km/l, depending on the transmission. Real world fuel economy, however is often not what the car manufacturers say for many reasons including driving conditions, traffic and driving style. What owners of the Sonet Anniversary Edition have been reporting in terms of fuel efficiency, has led to a discussion about how the car actually performs in day to day use. Some users are getting close to the claimed figures, but others are finding a significant difference. It has caused debates about how accurate manufacturer claims are, how different driving conditions affect economy, and how the Sonet compares to its rivals in terms of real world economy.