Aston Martin was the first team both to unveil a real 2022 car and shake it down on track at a Silverstone filming day.
Chief technical officer Andrew Green made it clear at the time that having launched so early the team was ready to investigate ideas from other new cars, and that the AMR22 was likely to change rapidly through the season.
That process is already well in hand as the team reacts to the lessons learned since the start of testing in Barcelona.
“The car you're seeing now is nothing like the car we have in the windtunnel,” said McCullough. “And I'm sure that's the same for everybody, up and down the pit lane.
“As you're adapting your cars, and optimising your cars, there's going to be an element of that car is strong, and it's gone that way that we sort of half looked at before. So let's revisit the data we've already got.
“As Andrew Green has said we tried with this car not to drive ourselves into any cul-de-sacs.
“So of all the different solutions out there, from the packaging and philosophy side of things, we just thought we want to be able to have a bit of freedom not to lock ourselves in totally to just one philosophy.
“And that is the case, we're open to converging. I think for all teams there will be an element of convergence, but maybe not as radical as the extremes. It's very interesting time.
“I think for the aero design guys it must be information overload for those those people at the moment.”
McCullough stressed that the team had no idea that its PU partner Mercedes was pursuing the sidepod and cooling concept that it unveiled on the W13 in Bahrain.
Aston Martin buys its power units, gearboxes and rear suspension from Mercedes, but McCullough says that there were no clues in the packaging of the shared elements as to what direction its partner team was taking.
The slim sidepod arrangement of the W13, the result of the Brackley team’s pursuit of an ultra efficient cooling system, was the talk of the Sakhir test.
“We had no idea that that was coming,” said McCullough. “We don't share any of that kind of information. Rear suspension, gearbox, engine hydraulics, that's the stuff that we're sort of sharing.
“So the whole radiator package cooling side of things has nothing to do with our knowledge. I started seeing it on social media the day before, a lot of people were talking about it. And that was the first time I heard about it.
“I think that fundamentally, what you're seeing different with the Mercedes is just the packaging of the radiators that then feed into the heat exchangers.
“So up and down the pit lane, it's fascinating to see everyone's interpretation on sidepod design, that's obviously an area of freedom, and quite a powerful area for controlling the aerodynamics.”
In contrast the Aston Martin AMR22 currently has more traditional sidepods. However McCullough admits that the team is prepared to pursue alternatives as it develops its car.
“We've done a lot of testing with a lot of different parts and concepts and sidepods throughout the development phase,” he said. “And we've got some update parts which we are evaluating, a whole load of different solutions.
“Of course, you're going to look at what everybody else has done now, you've seen nine other teams' interpretations of the regulations. So there's always an element of convergence. But the Mercedes one is obviously quite different.
“And the aero design guys are deciding relative to the solutions they have at the moment, and what they're thinking of doing going forwards.”
McCullough said there has been much work to do in testing to get up to speed with the new cars and tyres.
"It's been the toughest six days of testing I've ever been involved with, just from having to be understanding what you're doing, and reacting to it, and trying to still get all the main test items done. You've got to map and understand the car, you've got to try to get the maximum performance out of the car.
“We don't want the porpoising. But also long runs, high fuel runs, tyre degradation, Barcelona is obviously very cold, here is very hot, quite unique, rough tarmac, we were trying to just understand and factor all that in also doing some testing, looking ahead to Jeddah, and some other races.
“So I'm quite happy that we've got through all the main test items that we wanted to get through, and the car's reacting and behaving as we think it should be doing.”
