Helmut Marko has expressed surprise at Ferrari and Mercedes seemingly being affected by porpoising during 2023 pre-season testing.
The issue caused problems for several teams in 2022, with the Silver Arrows amongst those to particularly struggle with their car bouncing.
Consequently, the FIA opted to increase F1 cars' ride height by 15 millimetres for 2023 to prevent the sensation reoccurring.
According to Marko, however, the issue has not completely disappeared from the sport, with the Austrian suggesting that Ferrari and Mercedes experienced bouncing at testing in Bahrain.
"Surprisingly, both teams suffered from porpoising again," the Red Bull advisor told Austrian outlet OE24.
"They did some fine-tuning at the chassis and it seems to be working now, but: did they drive at full power? How much fuel was in the tank?"
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Marko wary of competition from Ferrari
Marko remains unsure whether porpoising will disappear for good but, in terms of the pecking order in 2023, the Austrian believes that Ferrari may pose a challenge to Red Bull.
"They have increased the horsepower," he commented.
"On the straights they can beat us, but we compensate with the complete package."
It comes after Christian Horner questioned whether Red Bull's rivals, such as Mercedes, were showing their true form during testing.
All will become clear when the 2023 F1 season kicks off with the Bahrain Grand Prix on 3-5 March.
Ahead of the season-opening Bahrain Grand Prix, RacingNews365.com journalists Dieter Rencken and Michael Butterworth analyse where each of the F1 teams stands after pre-season testing.