Oil experts have called on the government to find new ways to subsidise diesel prices, target only specific groups of customers for help, and end the current blanket subsidy for all motorists.
Giving help to certain groups of diesel users would ensure more efficient management of the government's oil fund, said Praipol Koomsap, Thammasat University economist and former assistant to the energy minister.
He added that selective government support would be better than the current blanket subsidy because some motorists, unlike goods transport operators, use diesel for personal purposes.
The oil fund, currently valued at 7.14 billion baht, is used to subsidise bio-diesel and gasohol for motorists, as well as cooking gas users.
For bio-diesel, the government wants to keep prices below 30 baht a litre.
Authorities also have a price cap on cooking gas at 318 baht per standard cylinder.
The oil fund is expected to be exhausted by the end of this year, prompting the government to take out a 20-billion-baht loan.
Mr Praipol suggested the government modify the subsidy programme by handing out discount cards or coupons to targeted groups of diesel users, giving them support similar to the co-payment economic stimulus scheme.
"This measure will reduce a financial burden for the government in the same way it relieved the impact of lockdown on people during the Covid-19 outbreaks," said Mr Praipol.
He said he did not agree with the blanket subsidies as they do not change diesel motorists' driving habits.
Unnecessary road trips produce carbon dioxide emissions, which in turn cause global warming.
The government is promoting electric vehicles (EVs) through tax incentives and non-tax schemes. More measures to promote EVs are expected to be launched in December.
The EV policy will add a new financial burden on the government, said Kulit Sombatsiri, permanent secretary at the ministry of energy.
He said energy authorities are waiting for the government to approve the 20-billion-baht loan, which will allow the oil subsidy programme to continue until April next year.
Kurujit Nakornthap, executive director of the Petroleum Institute of Thailand, suggested authorities cap the subsidy price at the higher price of 33-34 baht a litre to reduce the financial burden.
Disathat Panyarachun, senior executive vice-president of PTT Plc, said global oil prices are expected to stay above US$90 per barrel in the fourth quarter before decreasing to $75-58 per barrel next year.