Red Bull has issued an ominous warning to its F1 rivals that its RB18 has so far proven to be competitive without the team "even trying".
Across the five days of pre-season testing so far a different team has been fastest at the end of each day, yet Red Bull has not been one of them.
The team has promised upgrades and a performance push for the final day when it plays more of its hand ahead of the season-opening grand prix.
On day two, reigning champion Max Verstappen had a full day behind the wheel, finishing third quickest and eight-tenths of a second adrift of surprise package Kevin Magnussen on his return to Haas.
Reflecting on the day's running, head of race engineering Guillaume Rocquelin said: “It was more of a stop-start day, mostly by design.
"We had a good continuous run yesterday, so today was more about exploring and testing different things.
"We spent more time in the garage making changes to the car and also taking more risks. We learned a lot and gathered a lot of information.
"I’m quite happy with what we found out, we are progressing in different directions and it’s all very positive."
Rocquelin then concluded: "We were reasonably competitive at the end without even trying.”
Verstappen, meanwhile, described the day as "pretty standard", although enjoyed an on-track duel at one point with Ferrari's Carlos Sainz.
"It was fun to have a little battle with Carlos, I think he was on a long run with more fuel and I was on a shorter run," said Verstappen.
"Once I caught him he started using DRS. I think he wanted to race as well.
"So far the car is pretty good but there are always areas to work on.”