China’s net exports of gasoline in August rose to the highest in 31 months as refiners exhausted their quotas before domestic demand for motor-fuel increases in September as a result of national holidays.

Overseas sales of gasoline exceeded imports by 530,137 tonnes in August, according to data e-mailed by the General Administration of Customs in Beijing yesterday.

That’s equivalent to 145,000 barrels a day, which is the highest since January 2011 and a 70% increase from July, data complied by Bloomberg show. Gasoline is motor-fuel used in cars and planes, according to the Chinese customs agency.

China National Petroleum Corp and China Petroleum and Chemical Corp, the nation’s biggest refiners, were granted quotas in July to export a combined 665,000 tonnes of gasoline during the third quarter, according to Shanghai-based energy consultant ICIS-C1 Energy.

China is the world’s second largest oil consumer.

“The refiners may have increased overseas supply before a peak in gasoline demand during a long holiday,” Jean Zou, an oil analyst with ICIS-C1 in the city of Guangzhou, said by phone.

“We might see very low exports for September.”