On the first day in Barcelona, Norris topped the speed charts while Mercedes seemed to have a little trouble getting to their best.
After an increase in dirty air made racing more difficult in recent years, Formula 1's new regulations in 2022 aim to allow cars to race closer.
Various pundits are tipping Ferrari to be at the top of the 2022 F1 pecking order, with the Scuderia impressing in testing.
The Finn completed only 10 laps in the Alfa Romeo C42, the least of any driver on the day, as his team struggled with reliability issues.
Barcelona was the first venue to showcase these new challengers, with the ten teams taking to the track for a three-day testing session.
Alfa Romeo became the final team to reveal their challenger's livery for the season, which they described to be a subtle nod to the past.
Horner also believes that the former race director received insufficient support, and he wished him the best of luck.
The Brit set the pace for McLaren on the first day of testing at the Circuit de Barcelona-Catalunya, finishing fourth overall.
Russell's morning time was still good enough for second place at the finish, while Perez and Verstappen finished third and fourth.
Formula One aimed to take a peaceful solution amid the growing tensions between Ukraine and Russia.