Ford Performance Racing and Brad Jones Racing have postponed planned pre-Pirtek Enduro Cup tests at Winton Motor Raceway until Tuesday due to forecast wet weather.
Although teams were greeted with dry conditions this morning, isolated showers are predicted to hit the region from midday.
Walkinshaw Racing and Nissan Motorsport have conversely elected to test today despite the weather, with the former's hit-out already scheduled to run across both days.
FPR team manager Chris O'Toole told Speedcafe.com that having Tuesday available made the decision to abandon today an easy one.
“We've packed it up and will try again tomorrow,” he said.
“It's inconvenient but we always had tomorrow booked as a fall-back day anyway.”
Teams may be forced to complete some wet running regardless, with showers also being forecast as a possibility for tomorrow.
While FPR's four cars remained in their garages this morning, BJR's #8 BOC Holden made brief track appearances in the hands of Jason Bright and News Ltd journalist James Phelps.
Walkinshaw, FPR and BJR will be joined on track at Winton tomorrow by Volvo Polestar Racing, which last week rescheduled its test to Tuesday after Robert Dahlgren's heavy crash at Sydney Motorsport Park.
Queensland based teams Red Bull Racing Australia and Tekno Autosports will meanwhile be in action on Tuesday at Morgan Park, with Erebus Motorsport testing at Ipswich.
All teams are scheduled to run their Pirtek Enduro Cup co-drivers, including internationals Alex Buncombe (Nissan), Oliver Gavin (Walkinshaw) and Alex Premat (Volvo).