Australian drivers are being advised to refuel their vehicles before Wednesday, when a 16-cent-per-liter increase in the fuel excise tax is set to take effect. The tax, which had been halved since April, will revert to a standard rate, impacting motorists already contending with cost-of-living pressures.

Peter Jones, chief of the Victorian Automotive Chamber of Commerce, urged drivers to fill up their tanks in advance of the price adjustment. "Motorists are already under cost-of-living pressure, so if you need fuel, it makes sense to fill up before the increase hits," Jones told AAP. He also emphasized the need for public courtesy towards service station staff, who are not responsible for fuel prices.

The Australian Competition and Consumer Commission (ACCC) has placed fuel retailers on notice, stating it will closely monitor price movements. Commissioner Anna Brakey warned that the ACCC "will not hesitate to take action if retailers make false or misleading statements about price movements or if there is evidence of anti-competitive behaviour."

Petrol prices had recently fallen to their lowest levels since February, but the excise tax increase is expected to push them up again. The temporary reduction in the excise was implemented to shield drivers from the impact of higher global oil prices. The reinstated excise rate will remain in place until August 2.

Prior to the impending increase, average unleaded petrol prices on Tuesday were $1.54 per liter in Melbourne, $1.55 per liter in Brisbane, and between $1.50 and $1.58 per liter in Sydney.

The timing of the tax adjustment coincides with school holidays or the approach of the mid-year break in many Australian states, a period when families often undertake road trips.

Treasurer Jim Chalmers stated that the reduced fuel excise had provided essential cost-of-living relief during a financially challenging time for households. "Our fuel excise cut is part of the story, but also we've seen some welcome developments in the Middle East playing out in global oil markets," Chalmers said.

Jones described the staged approach to tapering the fuel excise relief as a sensible short-term measure. "This staged approach is welcome because it recognises that fuel price pressure does not disappear overnight," he said. "A sharp return to full fuel excise would have added another cost shock at a time when many auto businesses are already managing higher operating costs across the board."