The start of Friday's track running at the WD-40 Phillip Island 500 has been delayed by heavy fog.
Running was scheduled to being at 0910 this morning with Aussie Racing Cars practice, though with limited visibility the track remained vacant.
Officials sent course cars out on track to assess situations, with Supercars currently prepared to sit out its opening Practice session unless conditions improve.
The opening Supercars practice session is scheduled for 1125.
Kumho Tyre V8 Touring Cars, Toyota 86 Racing Series and Porsche Wilson Security Carrera Cup are scheduled to take to the circuit prior to the opening Supercars sessions.