Rain which had been forecast for multiple days finally fell last night in the city's west and while the chance of further falls today in Eastern Creek has dropped slightly, it still stood at 80 percent.
Today being the day of the Repco Supercars Championship's all-in test, it is non-transferable, and hence the usual provision for bailing out within two hours of starting or by 11:00 local time does not apply.
Furthermore, there has been virtually no wet-weather running with the Gen3 cars so far but, for team bosses to whom Speedcafe.com spoke, the risk still does not outweigh the reward.
Spares are thin on the ground, with parts shortages having delayed the builds of cars in the first place, while a new, softer wet tyre will not become available until the opening event of the season in Newcastle next month.
Grove Racing's David Cauchi left open the possibility of sending out the Penrite Ford Mustangs in the rain, although that is hardly a definite.
“We haven't done much running in these cars at all, so some understanding of the car in the wet would be beneficial,” he said.
“But we'll only have last year's wet weather tyre, so we'll have to see if we still think it's going to be advantageous.”
Cauchi added, “It's absolutely a factor, the limited spares that we have. We have some mechanical spares and some bodywork spares that are somewhat limited, but that's just a call that we'll make at the time.
“It's always about learning. If we can learn something, we'll go out and learn; if we don't think we're going to learn anything, then we'll park it in the garage.”
Tickford Racing's Tim Edwards said, “If it's wet, I'm not sure how much running we'll do. I'm not sure that we'll learn that much.
“The '23 tyres aren't available yet – they will be for Newcastle – and there is quite a difference between the old and the new.”
PremiAir Racing's Matty Cook noted the prospect that the rain will clear and Sydney Motorsport Park will start to dry out during the day.
Until then, however, he too is not particularly willing to send his cars out.
“Very cautious; risk versus reward in the rain right now with this car,” said Cook of his approach.
“There's not a lot to be gained and everything to be lost.
“To be honest, the rain's not here all day; we'll probably at this stage sit out most of it and let the rain come and go.
“We're predicting a lot of rain overnight and possibly to the early part of the morning, so if we turn up and it's raining, we probably won't run, but we think by about lunchtime that's all going to be gone, so we'll definitely be out in the dry.
“But, the wet tyres we've got aren't the current tyre either, so you're not going to learn too much.”
Cauchi confirmed that prized enduro signing Garth Tander is set to drive both Cars #19 and #26 during the day, having been on-hand with Matt Payne and David Reynolds to shake down those Mustangs at Winton earlier this month.
At Tickford Racing, Declan Fraser has been ruled out of getting behind the wheel of the #56 Tradie Mustang due to illness.
However, its full complement of enduro co-drivers is set to get laps, following the announcement of Garry Jacobson, Tyler Everingham, James Moffat, and Zak Best for the Penrite Oil Sandown 500 and Repco Bathurst 1000.
Pit lane at Sydney Motorsport Park opens this morning at 08:30 local time/AEDT.