[1][2] Pourchaire signed with ART Grand Prix for the 2020 FIA Formula 3 Championship and ended the season as runner-up behind Oscar Piastri by three points.

In 2024, he temporarily raced in IndyCar with Arrow McLaren, initially to substitute for the injured David Malukas before being signed permanently, but later being dropped in place of Nolan Siegel.

He claimed another podium with fourth (due to a guest driver getting third) in Jerez,[14] and got a second and third places at the final round in Circuit Paul Ricard.

[32][33] In October 2019, Pourchaire attended the post-season test at Circuit Ricardo Tormo, participating in all three sessions with Carlin Buzz Racing and ART Grand Prix.

[53] Pourchaire slipped to 17th after a poor start in Race 2, but took advantage when other drivers were involved in incidents, including future championship rivals Piastri and Logan Sargeant.

In October 2020, it was announced that Pourchaire would make his FIA Formula 2 Championship debut at the final two rounds of the 2020 season at the Bahrain International Circuit.

Pourchaire qualified fourth and finished sprint race 1 in fifth, following passes on Ralph Boschung and Marcus Armstrong during the final few laps at Baku.

[73] Pourchaire broke and fractured his wrist on his left arm in a first-lap collision with Marcus Armstrong and Dan Ticktum during the feature race.

[89] Pourchaire finished his rookie season in Formula 2 with 140 points, good for fifth place in the championship, and was far ahead of teammate Lundgaard who had only 50 to his name.

Pourchaire would be hit with more bad luck as on the fifth lap of the feature race, he was forced to retire with a gearbox problem and therefore dropped to fifth in the championship.

[101] Pourchaire qualified second at Monaco, alongside championship rival Drugovich, as a red flag thwarted his attempts to improve his lap further.

[102][103] He made a great start, passing the stalled Hughes, Liam Lawson, and Doohan to finish the sprint race in sixth.

Despite a rocky start, Pourchaire progressed up the field in the sprint race, taking advantage of numerous incidents to finish seventh.

[123][124] As Drugovich finished only ninth, Pourchaire slashed his championship lead to 21 points heading into the summer break, reigniting the title fight.

[129] In the feature race, Pourchaire started on the harder tyres, but his strategy would fail to work as a safety car brought out by Marino Sato mid-race bunched the field up.

He made a last-lap dive on Jehan Daruvala to secure tenth place before a penalty for David Beckmann saw Pourchaire elevate to ninth.

[131] In Monza, Pourchaire was on a decent qualifying lap until Iwasa crashed and brought out the red flag, which left the Frenchman 14th on the grid.

[162] In the feature race, Pourchaire made early progress to second, but eventually fell back to eighth during a late safety car where rivals on fresher tyres passed him.

A timed overtake following the end of a virtual safety car moved him past Bearman for third, but the English driver would re-overtake him and Pourchaire would settle for fourth.

[167] During the feature race, Pourchaire pitted much earlier than the frontrunners, which caused him to struggle late on and finish in sixth place, losing more ground to Vesti in the standings as the gap extended to 11 points.

However, a second win eluded him due to a late safety car, with Jack Doohan on the alternate strategy pitting and rejoining right behind him.

Doohan dispatched him on the penultimate lap and Pourchaire settled with second place once more, but re-claimed the standings lead after Vesti failed to start the race.

After taking third, with championship rival Frederik Vesti failing to finish the race, it left Pourchaire 25 points in the lead heading into the final round.

[189] Pourchaire then withdrew from the championship altogether to participate in the IndyCar with Arrow McLaren;[190] he was replaced by Ben Barnicoat for the next round of the season at Autopolis.

[196][197] Pourchaire made his FP1 debut with Alfa Romeo at the 2022 United States Grand Prix, while also confirming that he would become the team's reserve driver for 2023.

[199] Ahead of the 2023 Singapore Grand Prix, Alfa Romeo announced that Pourchaire will remain the reserve driver for 2024, as Valtteri Bottas and Zhou Guanyu had been retained.

[204] Pourchaire's second free practice session of the year came at the Abu Dhabi Grand Prix, where he ran the C43 in place of Zhou Guanyu.

[209] On 18 April 2024, Pourchaire substituted for the injured David Malukas at Grand Prix of Long Beach in the 2024 IndyCar Series for Arrow McLaren.

[225] In November 2024, Pourchaire drove an endurance racing car for the first time, driving the Peugeot hypercar during the rookie test at the Bahrain International Circuit.

[227] Away from the track, Pourchaire relaxes himself by playing Call of Duty and Grand Theft Auto and is a big fan of the saga Star Wars.