On the first day in Barcelona, Norris topped the speed charts while Mercedes seemed to have a little trouble getting to their best.
The Brit set the pace for McLaren on the first day of testing at the Circuit de Barcelona-Catalunya, finishing fourth overall.
Russell finished sixth fastest after completing 66 laps in the afternoon session at the Circuit de Barcelona-Catalunya on Thursday.
Unlike other teams, McLaren did not split driving duties, with Norris driving the MCL36 for the entire day.
Lando Norris ended the first day of pre-season atop the charts, besting the time set by Ferrari's Charles Leclerc.
Lando Norris recently signed a new deal that will keep him in the team until the end of the 2025 F1 season.
Lando Norris mentioned tracks like Singapore and Monaco, both street circuits, as places where the new wheels could cause problems.
Daniel Ricciardo's career has been charecterised by daring, late-breaking overtake moves. And he is hopeful that he can do this more often.
One issue that has gone unnoticed until now as the sport transitions from 13 to 18-inch tyres that might cause some issues.
Lando Norris, for example, has recently signed a contract extension with McLaren that will keep him with the team for another four seasons.