The government is studying the feasibility of requiring automakers to publish fuel economy data taken under multiple conditions in their sales brochures just like the rest of the world does, transport ministry sources said.

If realized, companies would have to state fuel efficiency data figures in such specific conditions such as driving in town or on expressways, and not only an average as is currently the case, they said Friday.

The Land, Infrastructure, Transport and Tourism Ministry hopes to put the measure into practice around 2018, they said. The question of the difference between actual fuel economy and current car brochure data has been highlighted by Mitsubishi Motors Corp.'s recently revealed fabrication of fuel economy data.

Average data for fuel economy are stated in car brochures after examination under domestic standards, but the government plans to shift the standards to international criteria around 2018, pertaining to cars and trucks of up to 3.5 tons.

Based on international standards, the ministry is considering making it mandatory for sales brochures to state fuel economy data based on measurements taken in towns, in suburbs and on expressways, in addition to the average, according to the sources.

"We hope the discrepancies with the actual running data will become as small as possible," a ministry official said.