Ferrari's fast practice starts in Formula One's pre-season testing in Bahrain have caught the attention of rivals and alarmed Mercedes' likely title contender George Russell.
Russell told reporters in Bahrain on Friday that he was struggling to get off the line quickly, while seven-time world champion Lewis Hamilton had shown impressive speed in the red car.
Formula One's governing body has been evaluating a new race start lights sequence at the end of each test session, with cars lining up and a new five-second pre-start flashing blue warning light before the standard procedure kicks in.
The change reflects added complications of the new power units, some of which appear to take longer than others to get the turbo running at the correct speed to ensure a quick getaway.
"I think we've got a lot of potential beneath us," said Russell, already installed as the bookmaker's early title favourite. "But to win a race, you've also got to get off the line quite well.
"And I think the two starts I've made this week were worse than my worst ever start in Formula One. And, Lewis, down in P11, got into P1."
McLaren's Oscar Piastri, whose car has the same engines as Russell's, sounded less concerned.
"I thought mine yesterday wasn't too bad. I was last but I think I passed about four cars as well. I think it's just very random at the moment, and I think we're all kind of learning what makes a good start, what makes a bad start," said the Australian.
"Just the way we do starts is much more difficult than last year. It's trickier from every single angle. And I think what we're seeing at the moment is people just getting things right and other people getting them very wrong."
Piastri expected the field to converge pretty quickly after the early races.
Apart from the starts, Russell said Red Bull appeared to have the best energy deployment of any team, but Mercedes were closing the gap.
The season starts in Australia on March 8.