The #230 Nissan test car that ran alongside 2024 cars from rival GT500 manufacturers Honda and Toyota featured minor aerodynamic changes compared to the current Z challenger, which made its debut last year.
With the GT500 regulations unfrozen next year, Nissan has taken the chance to base its test mule on the NISMO version of the Z road car that was released to the public last summer and will go on sale later this year.
However, Nissan's SUPER GT executive director Motohiro Matsumura says the firm wishes to evaluate the new bodywork further in subsequent tests before it makes a final decision on its introduction.
"We were able to confirm some of the characteristics of the #230 [test car] at the Okayama test," Matsumura told Motorsport.com. "This is the start of the development.
"We are using the exterior body shape of the NISMO Z [road car]. But it is not finalised [for 2024]. During the test we were able to make some comparisons [compared to the current car]. We don’t have to make a final decision until March next year.
"Even if the body shape of the two cars look very similar, the scaling creates some detailed differences with the flick box and lateral duct. These areas combined with the NISMO shape, we intend to confirm step by step.
"The Okayama test was just the first step to confirm the effectiveness of the aerodynamics."
Testing duties at Okayama were carried out by Team Impul and its drivers Bertrand Baguette and Kazuki Hiramine using Bridgestone tyres.
With Nissan having to search for a replacement tyre supplier for its two NISMO-run cars after Michelin departs at the end of the season, the decision to give the 2024 car its first run on Bridgestone tyres could be considered significant.
However, Matsumura insisted that the choice of drivers and tyres for last month's test was made for "scheduling" reasons.
"At the Okayama test, the other manufacturers were using Bridgestone tyres, so it was the easiest from a servicing standpoint to use the Impul crew, supported by NISMO," he explained.
"Usually we test first with the #23 crew, but this time we changed the sequence. It doesn’t indicate any specific intention."
Matsumura clarified that the next test for the 2024 GT500 car, slated to take place at Motegi early next month, will be undertaken with Michelin tyres.
"Even though they will not provide us with tyres next year, the characteristics of the aero [of the new car] need to be compared to the existing car using the same tyres," he said. "This is very important."
Matsumura dismissed suggestions that its choice of tyre brand could impact the driver line-ups for the two NISMO machines in 2024,
"It’s true that it’s an advantage for a driver to have that experience [of the tyre NISMO will use]," he said. "That experience of a different tyre can be very effective for development.
"But for 2024, we have a new car, so the reference is the existing drivers. The tyre is not the main factor to select drivers."
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