South Korea will have a more realistic system of indicating the fuel efficiency of cars from next year. The government has responded to criticism that there can be a large discrepancy between official and real-life fuel figures.

The current fuel economy rating system is based on city driving alone; the new one will be based on the US five-cycle test, which highway driving, cold temperature operation, high acceleration, city driving and an air conditioning test.

Fuel economy labels on cars rolled out from next year will show fuel efficiency not just in city driving but also in highway driving and a combination of both.

The official mileage of the Kia Morning (Picanto) is 18km/l (approx 51mpg) but when measured under the new system, it loses some 30% of that rated number, declining to 12.6km/l (36mpg) according to data disclosed by the parliamentary committee on knowledge economy. The Hyundai Avante hybrid’s fuel efficiency is reduced from the officially stated 17.8 km/l  to 12.6.

The new system will apply to all passenger cars and 3.5-ton or smaller trucks newly registered starting next year and to existing vehicles starting in 2013, the ministry said. The Korean government also plans to launch a website that lists information on the annual fuel costs for cars of different fuel types and engine displacements.