Peugeot notched up its first podium finish with the 9X8 in the last round at Monza, with Jean-Eric Vergne, Paul di Resta and Mikkel Jensen finishing third in the #93 car behind the winning Toyota and the second-placed Ferrari.
The breakthrough result came exactly a year after Peugeot made its WEC Hypercar debut at the Italian track, and followed a tough period in which it was bogged down by both unreliability and a general lack of pace.
With the French manufacturer having also shown strong speed in the preceding event at Le Mans, its Hypercar rivals now have a genuine reason to believe that it will be competitive in this weekend's six-hour fixture at Fuji.
As per WEC's Balance of Performance rules, Peugeot drivers will also be able to deploy hybrid power at just 135km/h compared to 150km/h, a factor that could play into its hands according to Le Mans 24 Hours winner Ferrari.
"Peugeot is a bit underestimated because as I said at Le Mans it was pretty competitive and the performance they showed in the first part of the race before the crash for Menezes was huge," Ferrari's sportscar race and testing manager Giuliano Salvi said.
"Here we need not forget but they have activation point at 135km/h in dry conditions. It could be quite an important factor. And at Monza anyway, they were on the podium.
"Peugeot at the start had quite a lot of problems for reliability, but now they seem a bit more reliable. I wouldn't be surprised to find them in the mix on Sunday."
Despite completing three full races last year as part of a partial programme, Peugeot continued to suffer from serious reliability issues at the beginning of the 2023 season.
This led to some pessimism about the French manufacturer's ability to get on top of the issues, but it has since quickly turned around its fortunes, even leading at Le Mans on pure race pace during the night.
Porsche's Frederic Makowiecki was impressed by the progress Peugeot has made in its first endurance programme since the 908 HDi FAP, saying both the work done on the reliability front and BoP changes have made it a bona fide podium contender.
"They have made a big step," he told Motorsport.com. "There are two, three factors. The first one is they improved the reliability a lot, definitely. And then there have been some [BoP] adjustments that they made them to be back in the game."
Toyota's Ryo Hirakawa also played up Peugeot's prospects for Fuji, with its hybrid deployment likely to be a big boost while accelerating out of slow and medium-speed corners.
"Last time at Monza Porsche was fast, and especially Peugeot can use the [hybrid] motor at a lower speed, so I think they will be a threat.
"At Monza when we went out, it was a bit surprising [how close everyone was], and it doesn't seem like anyone will be in a position to win by a large margin, so I think it will be close again."
Hirakawa's team-mate Brendon Hartley added: "Peugeot took their first podium at Monza and I think [with] the BoP they should be really challenging for the victory, from what I can see. You can't write anyone off."
Additional reporting by Jamie Klien
