Out of all newly registered passenger cars in 2013, gasoline cars stillconstitute 52.7 percent, compared to 32.4 percent for those running on diesel. But thenumber of diesel-powered passenger cars is growing fast, having risen from 18.5 percent in 2009.

Car dealers attribute the diesel car boom to thepopularity of sport utility vehicles forleisure activities, the fact that diesel costs less than gasoline and the higher fuel efficiency offered by diesel cars. The preference for diesel cars is especially strong in the imported segment, where diesels accounted for approximately 70 percent of salesin the first two monthsin 2014, the association reported.

Lubricant companies monitor such trends as vehicle populations, although this shift does not require a dramatic change in the engine oils they offer.

It is a notable change in the auto market, Cho Taebum, of GS Caltex, told Lube Report Asia.Lubricantmanufacturers here offer diverse oils for diesel engines andoils that meet specifications for both gasoline-powered cars anddiesel- powered cars. Lubricant businesses have enough technology and capability to supply diesel engine oils [that the market demands]. For now, gasoline cars are stillthe majority.

South Koreas Ministry of Land, Infrastructure and Transport reports that there were 19.4 million vehicles registered in the country in 2013,of which 9.3 millionunits are gasoline cars and 7.3 million units are diesel cars.