With McLaren having already run a Mercedes engine in the hybrid era, it's maybe not surprising that the switch back to the manufacturer from Renault for this year has gone so smoothly.
McLaren were the only team to change engine supplier for this year, resulting in a rethink on how to package the engine in a car that had been designed around Renault's architecture. But, not only did McLaren's MCL35M hit the ground running in pre-season testing, their unique diffuser design stole a march on the rest of the field and seemed to negate quite a bit of the rear downforce loss from the regulation changes.
The car has been put to good use, at least on Lando Norris' side of the garage, and McLaren are embroiled in an intense battle with Ferrari over the best of the rest spot behind Red Bull and Mercedes.
It's a long, long way from the trials and tribulations of the Honda-era McLaren of just a few seasons ago, with Andreas Seidl's calm and measured approach under Zak Brown's leadership yielding clear results.
Ferrari have the advantage of two drivers firing on both cylinders, suggesting McLaren should be able to cover them off with a more consistent car if they can help Daniel Ricciardo get over his issues.
It's been a great showing from McLaren this year, re-establishing the McLaren-Mercedes partnership that was so successful in the past.
Taking a clear step forward with the 2020 car tweaked for this year was no easy task, but the team managed it with aplomb, as well as shoe-horning in an engine the 2020 car wasn't designed for.
High point: Austria. Lando Norris' speed at the second weekend at the Red Bull Ring was, as near as dammit, on par with Mercedes. Had Norris not been given a questionable penalty for his incident with Sergio Perez, the British driver would have been ahead of Valtteri Bottas on track at the point where Lewis Hamilton started suffering with his damaged car.
With McLaren not quite able to match Red Bull and Mercedes on race pace in general, Austria showed the team are ready to rejoin the big leagues when the car is capable.
Low point: Hungary.
The Hungarian Grand Prix was the only occasion on which McLaren have left a race track empty-handed this season, and they were completely innocent of blame in the incidents that cost them so cruelly.
Norris was in the mix at the front into Turn 1 when Valtteri Bottas committed the cardinal sin of failing to brake in time in the wet, and was powerless to stop his McLaren from sliding straight into Max Verstappen's Red Bull after being pushed wide.
Further back, Daniel Ricciardo almost, almost made it through Turn 1 and could have been in for a great race. But he was tagged and spun by Charles Leclerc's Ferrari who, himself, had been hit by Lance Stroll's Aston Martin. Ricciardo managed to keep going but, like Verstappen, had too much damage to make any sort of impression on the race.
Lando Norris: Formula 1's best driver in 2021?
Given how Lando Norris picked up a somewhat unfair reputation as a 'joker' during his first year to 18 months in Formula 1, he took the conscious decision to distance himself from the social media fanaticism that surrounded him in order to go through a change of image, feeling that he wasn't being taken seriously.
Any doubts that Norris isn't the real deal, and I include myself in those doubters, have been well and truly proven wrong over the first half of this season.
Norris has, quite simply, been a sensation and it's completely understandable why he, along with Max Verstappen, top the fan vote for 2021.
Knocking out strong result after strong result, Norris proved more than able to join in the fight at the front when his car was capable, as shown in Austria. Had he not been the innocent victim of a stupid mistake from Valtteri Bottas in Hungary, Norris would likely have been the only driver to score points in every race so far this season.
Third place in the Driver's Championship is ample reward for what has been a tremendous display from Norris. To make it even more impressive is the fact that he has thoroughly dismantled the highly-rated Daniel Ricciardo in the second car.
Sure, Norris has more experience with the McLaren car, and the McLaren way of working, but the gap has been eye-opening on occasion. In Monaco, a circuit Ricciardo has won at in the past, Norris lapped the Australian.
Norris gets an A+ for the first half of 2021 because, let's be honest here, there isn't really anything to mark him down for. There aren't any particular signs of weaknesses, no silly mistakes, and he's maximised the car at every opportunity. To be ahead of a factory Mercedes and a Red Bull driver at this point of the season shows the extremely high standard at which he is driving.
Daniel Ricciardo: A puzzling disappointment
The highly rated Australian came into 2021 with one of the best reputations on the grid, but goes into the summer break with that reputation thoroughly battered.
Ricciardo has struggled immensely to get to grips with the MCL35M, unable to brake as late, carry as much apex speed, or get on the power as early as Norris is able to in the other car. Swapping chassis around in the first half of the season, at undisclosed races, failed to change the pecking order, and the chassis has been ruled out by both McLaren and Ricciardo as being the issue.
After a dreadful start to the season, there has been signs of improvement recently, with Ricciardo managing seventh in Styria (while Norris was fighting with the leaders), and coming home fifth at Silverstone, just 14 seconds behind Norris.
Ricciardo said after Silverstone that the battle with Carlos Sainz behind meant he felt he was driving more naturally, suggesting that the Australian is not at ease with the car to the extent where he is consciously trying to drive it, rather than relying on his natural instincts.
If Ricciardo was a rookie, it would be difficult to see him being given a second season, so vast has been the difference. Luckily for him, his past successes will buy him the time to get into the new regulation phase and a fresh start alongside Norris. But, if 2022 is more of the same, Ricciardo's goose is cooked.
If McLaren had two Daniel Ricciardos, the MCL35M would be regarded as a solidly midfield machine. While the differences between Norris and Ricciardo have been night and day, Ricciardo hasn't caused any stupid accidents or additional headaches for McLaren.
Added to that, his attitude is very much 'mea culpa', rather than pointing the blame at anyone but himself. That honesty has bought him a more patient response from the team, than if he had been accusatory about the imbalance. Fingers crossed he can get it together in the second half of the season.