An electric vehicle (EV) is shown in a motor show held by the Tokyo metropolitan government on Hachijojima island to spread EVs. (Provided by the Tokyo metropolitan government)

Automakers will be obliged to meet stricter fuel-efficiency targets as part of long-term efforts to curb harmful emissions to usher in the age of electric vehicles.

The government will require an average 32.4 percent improvement in fuel efficiency by fiscal 2030 compared with actual performance in fiscal 2016, meaning that the average vehicle will run 25.4 kilometers or more per liter of gas.

The tightened standard was revealed and approved at an experts' meeting jointly held by the transport and industry ministries on June 3.

The government will officially decide on the new standard within this fiscal year after hearing opinions from the public.

Each automaker will be required to achieve the stricter target as an average for all shipped vehicles, meaning that not every type of vehicle will have to meet it.

The current standard, compiled by the government in 2011, requires vehicles to run an average of 20.3 km or more per liter of gas by fiscal 2020 under the current fuel efficiency measurement method.

Under the measurement method of stricter criteria, 20.3 km per liter is equivalent to 17.6 km per liter.

Automakers have already met the current standard partly owing to the spread of hybrid vehicles. The government decided to create the new standard to reduce carbon dioxide (CO2) emissions further.

The stricter standard will improve the fuel efficiency by 44.3 percent compared with the current one.

While the latter has been applied mainly to gasoline-powered vehicles and HVs, the new standard will also cover EVs and plug-in hybrid vehicles (PHVs).

Although EVs do not use gasoline, CO2 is still indirectly a problem because electricity for the chargers is produced by thermal power plants.

Under the new standard, fuel efficiencies of EVs and PHVs are calculated based on a special method that shows how many kilometers per liter of gas they would get if they were powered by gasoline.

According to the transport ministry, EVs currently on the market get more than 40 km per liter under the special calculation method.

Carmakers are expected to step up their R&D and sales of EVs to comply with the new standard.

New EV and PHV sales in Japan in 2017 totaled 54,000, accounting for only about 1 percent of all the new domestic sales that year.

By introducing the new standard, the government aims to raise the figure to between 20 percent and 30 percent by 2030.

Stricter standards are very much a global trend. Though a simple comparison is impossible, as measurement methods are different, the European Union discussed the next goal to be achieved by 2030.

As a result, the CO2 reduction target was raised more than 30 percent from the current one, according to the transport ministry.

Britain aims to end sales of gas-powered vehicles and diesel cars by 2040.