Why Mercedes was so confused by its diva

"I'm proud of its flaws because she's not been perfect," was Lewis Hamilton's verdict on the Mercedes W08 on the day he won his fourth world championship. "While people have written that we've had the best car, I don't believe we've had the best car. I think we've been the best team."

Inarguably, and although Lewis sealed the title with two races to run, this has been the tightest season of the hybrid era. The popular narrative - one that's already been documented extensively - has it that Lewis claimed the silverware in spite of a car that swung needily between being devastatingly quick and infuriatingly high maintenance.

Had Sebastian Vettel not had his moments of madness in Baku and Singapore, opening into a wider rosso corsa implosion on the Asian leg, the outcome might have been different.

Indeed, Vettel led the standings for much of the year while Mercedes' performance fluctuated between weekends - and even during them, depending on the tyre compounds available and if the track temperature changed. In Monaco Hamilton even failed to make Q3 when he was unable to bring the tyres on both axles up to their peak.

"You can say there is certain DNA in a car, and we have proved our car can go very quick in qualifying and in the race," said team boss Toto Wolff after that debacle. "But it seems to be more a bit of a diva to get it into the right window."

Mercedes continued to suffer the occasional off-weekend, or off-session, for the rest of the season, seemingly confirming the impression that the W08 didn't want hotel staff making eye contact, and had a preference for all the blue M&Ms to be removed from the bowl. But is this genuinely the case, or are we underestimating how much more competitive the resurgent Ferrari have been this year?

"We've always made cars that are a bit diva-ish - all teams have," says chief designer John Owen. "When you have a half-a-second advantage [per lap], as we might have done in previous seasons, on the days the car is misbehaving you're potentially still going to win anyway. And on the days it's working really well, you don't drive it as hard as you possibly could, so as to preserve the engine. You smooth out the ripples of performance across the course of a season.

"Singapore 2015 is quite well-documented as one of our low moments from that year. But then we weren't great there in '14 either, and went on to only just winning in '16. There are certain circuits that don't suit the car, and we go into a weekend expecting that.

"The main thing with this year, I think, is that Ferrari have done a great job and have been much closer to us. When you've got a close competitor, and your car has a bit of a wobble, they're ahead of you - and it becomes a crisis because you're not winning."

The reason for weaknessess at particular circuits - or in certain conditions - recurring from year to year is that most teams carry over the essential philosophy of their cars from one to the next, thereby (as Wolff alluded) encoding certain characteristics into their proverbial DNA.

It's a pivotal decision, fraught with perils: in choosing to start again from a clean sheet, with a completely new car concept, a team might have to abandon a vast trove of accumulated knowledge. Optimising the new concept might take months - or even entire seasons.

"Unfortunately, most of the things we had to adapt to we hadn't seen coming. So we carried a lot of compromise through the year for things that didn't need to be changed and we struggled a bit with those that did"
Mercedes chief designer John Owen

Most teams now copy Red Bull's nose-down, tail-up car philosophy to some extent, but some have taken longer than others to get the most out of it - McLaren, for instance, are arguably only now on top of it, having first gone down that route in 2013.

That's because it's one thing to copy a car's external aero features from pictures, quite another to understand how the overall aero 'map' works, how it changes in different conditions, and how the suspension has to be managed to give the aero a consistent platform.

It's interesting that Mercedes hasn't gone high-rake yet - and neither has Williams, albeit with diminishing returns in its own car concept. Even before the hybrid power unit regulations came in, Mercedes fielded cars that were noticeably more flat to the track surface, relying on clever hydraulic systems within the chassis to remain so.

But the FIA has been clamping down on those systems, first outlawing active interconnected hydraulics, then at the beginning of 2017 banning the passive systems several teams are believed to have developed. That means Mercedes may have to consider change in future.

"I wouldn't say we're particularly hung up on anything on the car," says Owen. "We're happy to change anything about it. There are areas where we're different; the front-end aerodynamic philosophy of our car is pretty much unique, although Toro Rosso have some similar elements this season. Other than that, the narrow nose, and the things that go with that further down the car, are areas where we're unique.

"That was carried through from the 2016 philosophy, and there were other areas, such as the suspension, that were similar to before, but then you get to new areas, such as the bargeboards, where the W08 is very different. There were a few things we'd done on the 2016 car, the W07, at the front, the floor, that helped us in our understanding for 2017.

"We knew the rule change was aimed at shaking up the grid and that it would be a massive challenge to stay in front. We had to get the balance right in terms of how much resource we put into the W07, and how much we put into this one. It was a question of starting strong in '16, and then when we'd done enough, very quickly moving as much effort as we could into the new car."

The 2017 regulations presented several unknowns, chief among those being how Pirelli's wider tyres would work. 'Blind' pre-season tests with mule cars provided mixed results ("Looking back, I think we could have done a better job, or got more out, of the tyre testing," says Owen).

It was a double moving target: the mule cars were ballasted up to the right weight, but had nothing like the downforce required for Pirelli to accurately assess loadings. That meant both the teams and the official tyre supplier embarked upon the season not knowing what to expect, though some took a more positive view.

"It's always nice to have a regulation change," says Owen, "because [in a stable environment] you can get a little too focused on the detail. A rule change takes you back to first principles. From a designer's point of view that's a very enjoyable thing to do.

"I set the objective to build a 90% car for 2017. It might seem strange not to aim for 100%, but the problem you face in any new set of rules is that you can't be certain of the challenges you'll face along the way - how the rules evolve, whether the tyres behave differently from how you expected.

"There's a lot of unknowns there, so you aim for a car that can cover as many different circumstances as possible, and accept that it might not be the pinnacle of optimisation. That tends to come in the second or third year of regulation stability.

"We built a lot of adjustment into the car, the capability to react to things we saw. Unfortunately, most of the things we had to adapt to we hadn't seen coming. So we carried a lot of compromise through the year for things that didn't need to be changed and we struggled a bit with those that did.

"What I mean [by 'a 90%' car] is that it's quite spacious in places. The reason for that was to enable us to react during the design process and move things round. We didn't know where the aerodynamic development would take us, to some extent - what areas of the car we'd need to find more space on for aero performance, what areas were safe zones where you don't find any aero. If you can move things around in the car and not have to reinvent every part of it with every new development, it's quite wise.

"We did have a very late change to one aspect of the power unit, and because of our philosophy we could accommodate it reasonably well. If that had happened on our 2016 car it would literally have been a case of tearing up the design and starting again. It was nice to have that little bit of breathing space, whereas for the next car we can afford to be a lot more aggressive."

The W08 has racked up 12 wins out of 20 grands prix, a respectable tally even if at least two of those victories eventuated through Ferrari - or their drivers - blundering. But that doesn't mean Mercedes have misgivings about moving on, conceptually speaking. Technical director James Allison has spoken of aiming for a car that's easier to "throw at a racetrack" and extract the maximum from.

"You think this car is a little bit tricky," says Owen, "but it's not massively more so than the others. If it were two-tenths faster, it would seem to be a lot less of a diva than people say.

"Having said all that, we know of a few things on this car that made it a bit tricky. Hopefully we'll have them fixed for the next one..."