Vehicles covered
A Singapore-registered motor vehicle leaving by land must have at least three-quarters of a tank. ICA’s page covers diesel, petrol and compressed natural gas (CNG); a petrol/CNG hybrid must meet the level in both tanks.
Failure and example
Non-compliance can lead to a fine, prosecution or a required U-turn. For example, filling only the petrol tank does not satisfy the stated rule for a vehicle also running on CNG. Consult the Customs guidance linked by ICA for detailed application and exceptions.
Official ICA source
Written independently from ICA’s English original. The linked source supplies the complete document and subsequent updates.