South Korea’s Ministry of Land, Infrastructure and Transport will start implementing tougher mileage verification tests to determine vehicle fuel efficiency ratings. A total of 23 different models, representing 64% more than last year, will be subjected to test verification, the ministry said. Some vehicles will undergo fuel efficiency, as well as safety, tests.

Until last year, three different ministries carried out fuel efficiency tests. The trade ministry released fuel efficiency data under the category of energy conservation, while the land ministry conducted it for vehicle safety and the environment ministry did the same for greenhouse gas emission control.

A dispute arose after Hyundai Santa Fe’s fuel economy was given a valid mark by the trade ministry, but an invalid mark by the land ministry. This caused an industry-wide call for unified fuel efficiency test standards.

Last November, the vehicle mileage test was assigned exclusively to the land ministry, which has been tightening its methodology. From this year, the fuel efficiency rating on city roads and highways should each come within a 5% margin of error. Should vehicle makers get a failing mark, they could face mandatory recalls and be forced to pay compensation to their customers. Previously, the combined fuel efficiency rating for city and highway driving should come within the 5% margin. One vehicle will be sampled for a test, but if its fuel efficiency is suspected to be different from the same model, an additional three vehicles will be sampled again and the four results will be averaged.

The first test will be done by the Transportation Security Authority under the land ministry, while the second will carried out by five organizations under either the trade ministry or the environment ministry.