Valtteri Bottas has revealed the porpoising experienced by F1's new cars during the first pre-season test is making vision "tricky".
The new generation of machinery utilises ground-effect aerodynamics in an attempt to allow cars to follow each other more closely through corners.
But the airflow and pressure increases caused by the ground-effect is leading to aero stalling at the rear of the car floors, resulting in vigorous bouncing of cars in a straight line, known as porpoising.
Some teams have experienced the phenomenon more than others, with McLaren seemingly escaping the lightest.
Asked how he was affected by the bouncing, Alfa Romeo driver Bottas said: “I would say it affects a bit of everything. It is not very comfortable if it happens.
"Visually it gets a bit tricky and obviously, you lose overall load because the level of the downforce goes up and down and it can affect the braking as well.
"One concern, obviously, if you carry on like that is the reliability of certain parts in the car so I think that is quite a new thing for every team to learn and how to deal with that and optimise the set-up to avoid it.
“I would say it has been a bit of a challenge for everyone.”
Bottas was only able to complete 55 laps during the Barcelona test, with a second opportunity to rack up mileage with his new team beginning March 10 in Bahrain ahead of the season opener at the same venue.