Lando Norris played down McLaren’s advantage at the Bahrain Grand Prix after team-mate Oscar Piastri led him to a one-two in Friday practice.
Piastri was 0.154 seconds quicker than Norris while Mercedes’ George Russell was 0.527secs behind the Australian in third place, ahead of Ferrari’s Charles Leclerc.
Red Bull’s Max Verstappen, winner in Japan last weekend, was down in seventh, 0.825secs off the pace.
Lewis Hamilton was one place further back in his Ferrari, 0.246secs behind the Dutchman.
But Norris said he believed McLaren’s apparent advantage was purely down to McLaren’s rivals running their engines in a lower power mode.
“Everyone just looks at the timesheets,” Norris said. “They have no idea on the information on who turns up (the engine).
“It’s (worth) like 0.35secs around here. That immediately puts us back in the same position as the Mercedes, so at the minute I wouldn’t say we’re any quicker.”
But Russell said he believed McLaren were “a big step ahead”.
“They are a long way ahead in the middle sector, where the tyres are overheating,” Russell said.
“A bit of work to do but I think we’re fighting for next best. I think it’s going to be close between us, Ferrari and Max. But unlike the first three races, I feel this race won’t be dominated by qualifying, it will be dominated by race pace and tyre degradation.”
Ferrari have a revised floor which they hope will move them closer to the pace after a disappointing start to the season.
Leclerc said it did what was expected, and Hamilton said it was “definitely working”.
The seven-time champion added: “It’s good to see we’re taking steps forward and we are trying to extract more from it. I hope we can make the right steps tonight into tomorrow.”
Verstappen said: “The gap was quite massive. I’m not entirely happy, just struggling a lot with grip. The balance wasn’t too bad.
“Quite a bit of work to do also in the long run, just too slow every lap basically, not a lot of fun out there on the long run. A bit of drift practice there at the end as well.”
McLaren’s advantage on the race-simulation runs appeared as large as on a single lap.
Corrected for fuel load and engine mode, Norris was just over 0.2secs a lap on average ahead of Russell, with Hamilton a similar margin further back and just ahead of Verstappen.
Piastri and Leclerc did their long runs on a different tyre compound so their times cannot be compared.
Mercedes’ Andrea Kimi Antonelli was fifth fastest, from Racing Bulls’ Isack Hadjar, Red Bull’s Max Verstappen and Ferrari’s Lewis Hamilton.
Briton Oliver Bearman was ninth fastest in the Haas ahead of Williams’ Carlos Sainz.
The sessions were relatively incident-free on a track with which the teams were familiar after three days of pre-season testing a month and a half ago.
McLaren also headed the first practice session, with Norris ahead of Alpine’s Pierre Gasly as six teams ran young drivers in their cars.
