Andre Heimgartner leads the timesheets at the midway point of the pre-season test at Sydney Motorsport Park.
In a landmark day for Supercars, all 25 brand-new Gen3 cars are sharing a race track for the first time.
The historic test day drew a large crowd to the Eastern Creek circuit, with fans lining the paddock, grandstand and track surrounds.
They were treated to a spectacle of cars in wet and dry conditions, with Heimgartner the benchmark in both wet and dry running.
The four-hour session begin under light drizzle, before conditions improved in the final two hours.
Heimgartner (#8 R&J Batteries Camaro) proved the quickest driver throughout the morning session with the Brad Jones Racing driver quickest with a 1:29.8268s.
The New Zealander set his benchmark with 12 minutes remaining, with Will Brown (#99 Coca-Cola Camaro) and Jack Smith (#4 SCT Logistics Camaro) rounding out the top three.
The Fords of Will Davison (#17 Shell V-Power Mustang) and David Reynolds (#26 Penrite Mustang) rounded out the top five.
Heimgartner’s teammate Bryce Fullwood — in 11th place — logged the most laps with 69 in the #14 Middy’s Camaro.
Rain affected the first half of the session
Reigning champion Shane van Gisbergen (#97 Red Bull Ampol Camaro) set the early running with a 1:42.7677s on his third lap, and improved to a 1:42.3966s by his 15th lap at the one-hour-14-minute mark.
Slowly but surely, track conditions began to improve; at the one-hour-14-minute mark, Heimgartner went fastest with a 1:41.8913s.
With two hours elapsed, 19 of the 25 cars had completed laps as they cycled through they programs.
Top spot changed several times in a matter of minutes, with Fullwood, Cam Waters (#6 Monster Mustang), Anton De Pasquale (#11 Shell V-Power Mustang) and Heimgartner all spending time in first position.
Notably, Fullwood and De Pasquale traded fast times before Heimgartner clocked the first 1:39s lap of the day.
Heimgartner set a 1:39.4979s on the two-hour-30-minute mark, with Brown and Reynolds also spending time in second.
BJR bolted dry tyres onto the #8 R&J Batteries Camaro, and Heimgartner made it work immediately.
With just over an hour remaining, Heimgartner fired in a 1:33.9397s, and went on with it with a 1:33.3653s.
Broc Feeney (#88 Red Bull Ampol Camaro) jumped to second with a 1:35.0327s ahead of PremiAir Racing teammates Tim Slade and James Golding before all cars returned to pit lane with 70 minutes remaining.
The entire field rolled out on dry tyres with an hour remaining, and Heimgartner again emerged the pace-setter with a 1:31.6559s.
With 52 minutes remaining, Fullwood (1:31.8251s), Macauley Jones (1:32.1115s) and Smith (1:32.2286s) formed a BJR lockout ahead of Davison, Waters and Mark Winterbottom (#18 DEWALT Camaro).
At the three-hour-17-minute mark, all 25 cars had turned a lap once Brodie Kostecki rolled out the #99 Coca-Cola Camaro.
Kostecki’s teammate Brown went to the top with a 1:31.1405s with 33 minutes to go.
It remained the benchmark once Heimgartner went fastest of all — and 1.3s clear at the top — with his 1:29.8268s.
Van Gisbergen ended up 23rd, just behind Waters and Chaz Mostert (#26 Optus Mustang), having logged 47 laps aboard his Triple Eight Camaro.
Thomas Randle (#55 Castrol Mustang) brought up the rear, having picked up a throttle issue in his Tickford Racing Ford.
Wednesday’s action — which is free to the public — will conclude with a second four-hour session from 1:00pm to 5:00pm local time.
The 2023 Repco Supercars Championship will commence at the Thrifty Newcastle 500 on March 10-12.
Tickets are on sale on Supercars.com and Ticketek.com.
2023 Sydney pre-season test: Morning session
*Declan Fraser's #56 Mustang being shared by Zak Best, Tyler Everingham, James Moffat and Garry Jacobson