The timesheets for the two-day test in the GT300 class were dominated by FIA GT3 machinery, with the fastest time coming on the opening day courtesy of Takashi Kogure in the #88 JLOC Lamborghini, followed by the K-Tunes Racing Lexus and Pacific CarGuy Racing Ferrari.
Just one GT300-rules car (formerly JAF GT300) breached the combined top 10 for the two-day test, the Saitama Toyopet Toyota GR Supra that topped the order on the second day of running.
Kohta Kawaai's best time in the Supra, a 1m25.917s, was good for fourth overall, but was almost seven tenths slower than Kogure's best in the JLOC Lamborghini Huracan GT3 Evo.
Last year, the previously dominant FIA GT3 cars won just two of the year's eight races, with Subaru's all-new GT300-rules BRZ winning the championship having scored four poles.
That led Kondo Racing's Joao Paulo de Oliveira, who shares a Nissan GT-R NISMO GT3 with Kiyoto Fujinami, to declare that the GT300 cars were "on another planet" at the end of last season.
Speaking to Motorsport.com at Okayama, the Brazilian driver dismissed the notion that the testing times showed that FIA GT3 cars could be back in the ascendancy.
"I don’t think the laptimes are representative at all," de Oliveira told Motorsport.com. "There are some cars driving up to two seconds a lap off their own pace.
"They show what they can do in private testing but not in the official GTA tests. They are not pushing at all."
On whether he expects to see a closer competition between FIA GT3 cars and their home-grown rivals, he added: "We’ll see what adjustments they make, because last year we had one dominant car in qualifying [Subaru] and their Balance of Performance didn’t change all season.
"Maybe things will change this season. But it’s something that is out of our hands."
Kosuke Matsuura, who shares the #87 JLOC Huracan with Natsu Sakaguchi, offered a similar assessment to de Oliveira.
"I don’t know what the JAF cars are doing, I know they did some really fast times in the winter at this circuit," Matsuura told Motorsport.com. "I think when we come back for the first round next month, they may be five tenths or one second faster."
After setting his chart-topping time on Sunday, Kawaai told the official SUPER GT website that the GR Supra has been given a tighter air restrictor for this season.
Kei Cozzolino, who was at the wheel of the Pacific CarGuy Ferrari 488 GT3 Evo when it set its fastest time on Saturday, noted that the Supra's straight line performance indeed seemed lower than before.
"I heard some rumours that the Japanese [GT300] cars might be more restricted than last year," Cozzolino told Motorsport.com. "I was trying to find some of them on-track, I followed a Supra and they look a little bit slower in a straight line.
"You never know, they could just be sandbagging. But if it’s the case [that they have been slowed down] then I think we could have a good championship."
