What is dirty air?
The modern F1 car is known to completely distort the flow of air when it cuts through it. This disturbs the airflow that would normally flow over a chasing car to push it down and make it stick to the track in corners - the disturbed air behind a car is known as 'dirty air'.
What dirty air results in is that the loss of downforce makes it incredibly difficult to closely follow someone ahead, which in turn results in less overtakes as drivers aren't in position to go for a potential move.
While the 2021 rules are set to dramatically decrease dirty air, it will remain a problem in the upcoming season, as Ricciardo echoed when asked by GPBlog how it compared to 2019.
"It is pretty dirty,” the Aussie said with a big smile after completing his test on Friday morning.
“I feel we’re going quicker than last year again. Turn three’s an easy full [flat-out], turn nine is full more or less – but not with load fuel.”
Ricciardo, who set the second-quickest time on Friday (at time of press), will be right in the thick of the midfield fight in 2020 for Renault. He will therefore be a big victim of dirty air, particularly at tracks like the Circuit de Catalunya, as he explained himself.
MORNING SESSION = DONE— Formula 1 (@F1) February 28, 2020
Here is the final classification from Friday morning
Just one more session of preseason testing coming up - and it's on the way after the lunch break!#F1Testing #F1 pic.twitter.com/iGvAg776D1
"It's worse than last year"
“I think the dirty air we’re creating is more because of the speed we’re going. Long story short: you still feel it, and unfortunately on a track like this one with a lot of high-speed corners in the first two sectors it is very hard to stay close to the car [ahead].”
“I’d like to say it’s better, but no, it’s certainly not; [it’s] worse than last year.”
The seven-time Grand Prix winner is looking to bounce back in 2020 after a frustratingly inconsistent debut season with Renault, which started with a first-lap-retirement at his home race in Melbourne. Can he lead the way in midfield in the final year of his contract?