Overall oil consumption is likely to contract by 8.7% this year, a record decrease, to 144 million litres per day (MLD) on average, from 157 MLD last year, because of the Covid-19 impact, says the Department of Energy Business (DOEB).
The last time Thailand saw its oil consumption decline was during the 1997 financial crash, falling 0.4%, the first drop on record.
DOEB chief Nanthika Thangsupanich said the land and air traffic lockdown across the globe during the pandemic is the main factor for the sharp fall this year.
Her department announced its new estimate on Wednesday. Before the pandemic, it projected oil consumption to grow almost 3% in 2020.
According to the DOEB, this year's consumption of gasoline and gasohol will decrease by -3.1%, jet fuel -43%, liquefied petroleum gas -15.8% and compressed natural gas -4.8%.
Diesel consumption will only see a small increase by 0.4%, while demand for kerosene and fuel oil will grow by 94% and 11.3%, respectively.
Ms Nanthika said oil consumption typically follows GDP. The Bank of Thailand last month downgraded its Thai GDP forecast for 2020 to a contraction of 8.1% from a 5.3% decline projected in March.
During the first half this year, the DOEB said, oil consumption contracted by 13.8% to 138 MLD, from 160 MLD in the same period last year.
Consumption of gasoline and gasohol contracted by 7.6% to 29.7 MLD, diesel 4.9% to 65.6 MLD, jet fuel 48.9% to 10.2 MLD, liquefied petroleum gas 16% to 18 MLD, compressed natural gas 28% to 4 tonnes per day, kerosene 16.8 to 20,000 litres per day, and fuel oil 22% to 4.5 MLD.
Ms Nanthika said the drop in oil consumption will not change its plan to make biodiesel B10 the primary diesel for motorists, but officials may slightly delay the same move for gasohol E20.
In January the government announced B10, a mix of 10% palm oil-made methyl ester and 90% diesel, as the primary diesel to replace B7 formula.
It plans to make B10 available at all petrol stations nationwide by Oct 1.
B7 and B20 will be downgraded to alternative fuels.
Gasohol E20, a mix of 80% unleaded gasoline and 20% ethanol, was previously scheduled to be the primary gasoline, replacing E10, in the same period.
However demand for ethanol to produce hand sanitiser skyrocketed in the second quarter this year, delaying the plan.
The new date will be considered by the new energy minister, Ms Nanthika said.
The promotion of biofuels is based on a revenue-sharing concept, which allows farmers to sell palm oil and ethanol, made from cassava and sugar, to oil businesses.