How long until Vettel's patience runs out?

A Formula 1 team in need of a new star driver to bring focus to its ambition, around whom to structure a competitive recovery after a season of struggle; a multiple world champion driver in need of a fresh challenge and new motivation, after a difficult year of his own.

The aim is to shrug off a temporary slump and win F1 titles again. Things begin well, the driver wins several races in his first season with his new team; the team seems revitalised by his swashbuckling antics in the car, and substantially improves its fortunes in the constructors' world championship. But the following season progress stalls.

The team is relatively less competitive than before; the driver wins fewer races and drops further behind in the drivers' championship. Still both parties continue to make positive public pronouncements, declaring their mutual belief they are on the right path, that it is simply a matter of time.

This could easily be read as a summary of Sebastian Vettel's Ferrari career so far, but it is in fact the cautionary tale of his predecessor Fernando Alonso's first two seasons at Maranello.

Alonso drove magnificently during his five years at Ferrari, but gradually lost patience with its repeated failure to build cars capable of winning the world championship.

Of course he came mighty close in 2010 and '12, but even those seasons largely follow the overall narrative of Alonso's Ferrari career - overachievement against the odds and making the most of mistakes by rivals.

By 2013 there were rumblings of discontent, as Alonso grew frustrated by Red Bull's continuing dominance and Ferrari's inability to match it. His manager even held talks with the Milton Keynes outfit, after which Alonso was admonished by then Ferrari president Luca di Montezemolo for criticising the team.

Fearing Alonso would leave, Ferrari re-signed Kimi Raikkonen from Lotus for 2014, which ultimately blocked a potential move for Nico Hulkenberg when Alonso eventually decided to stay put.

But the final seeds of doubt were already sewn in Alonso's mind, and after a woeful 2014 season (Ferrari's only winless campaign since 1993) divorce finally came.

Alonso and Ferrari parted ways with collective ambition frustrated, the Spaniard returning to McLaren of all places, where his hopes of a long overdue third world championship now hinge on Honda's fledgling engine programme coming good before he retires.

Step forward Vettel, who like Alonso headed to Ferrari as a multiple world champion lured by the romanticism of racing for Formula 1's most famous team.

Their first season together was all sunshine and lollipops, as they won races and began to challenge F1's new dominant force Mercedes.

Vettel wasn't exactly a title contender, but he almost denied Nico Rosberg second place in the standings, and made confident statements about Ferrari's resources and potential following a winter of upheaval.

Sound familiar?

Vettel is by no means at crisis point yet, but surely his resolve will weaken if his burning ambition to add to the four world championships amassed with Red Bull remains frustrated by Ferrari's shortcomings.

Last season was all new faces, new opportunity, fresh environment and progress, but 2016 has arguably been a step backwards for Vettel and Ferrari.

Ten races into last season Vettel had amassed two victories, scored points in every race and stood on the podium seven times. This season he has retired from three of the first 10, won none of them, and amassed just five podiums - as well as fewer points than he managed at the same stage in '15.

The results are not there, and the performance of the car is not there either. If you average out the percentage pace gap between Ferrari and Mercedes in qualifying over the first 10 races of each of the last two seasons, Ferrari has lost ground to its main rival. In 2015 the average deficit was 0.835%; this year it is 0.913%.

Ferrari is now in real danger of being superseded by a resurgent Red Bull team, which has won a race this year, should have won two in fact, and was Mercedes' nearest challenger at Silverstone last time out.

Silverstone is the perfect indicator of Ferrari's weaknesses, a high-speed circuit where downforce is king. At the British Grand Prix it was clearly the third-fastest team, but more worryingly its percentage pace deficit to Mercedes increased from 1.226% in 2015 to 1.835% this year.

Ferrari's V6 hybrid turbo engine is clearly much better than the dreadful effort that powered its 2014 car, and not too far away from what Mercedes now has. But the SF16-H is not a match for the W07 in the corners.

Raikkonen admits Ferrari is lacking downforce, and it seems the car also has a narrow set-up window that makes it difficult to improve without significant sacrifices.

"We are missing downforce and at a place like this [Silverstone] it's not easy because of that," says Raikkonen. "I'm sure the next circuits are much more normal for us, but downforce would help any place. It's definitely what we need to challenge on every kind of circuit.

"That's not to say other areas cannot be improved - every area can be improved. But right now, in this kind of circuit, downforce is our biggest issue."

In Azerbaijan it was performance in low-speed corners; in Monaco and Spain it was how the set-up worked the tyres.

Silverstone may turn out to be a blip in the general form of this season for Ferrari, but the underlying trend is still cause for serious concern.

The SF16-H doesn't look an easy car to understand or extract performance from, and this clear downforce deficit is worrying for Ferrari when you consider next year's regulations will place even greater emphasis on aerodynamic development.

And as engine performance inevitably converges, the focus on aero will become even more acute. Arguably the balance is already shifting, benefiting the likes of Red Bull and McLaren-Honda, while Mercedes continues to hold its own at the front.

Ferrari has traditionally been weak in this area, arguably ever since it finished the 2008 season with the best car on the grid.

In 2009 it missed the trick with double diffusers; subsequently it was left behind in the race to develop the sort of exhaust blown downforce trickery that powered Red Bull so well until the end of the V8 era.

Now it seems to be struggling to develop an elite chassis as the fruits of engine development become harder to discover.

Alonso gradually grew tired of Ferrari's persistent shortcomings. Vettel continues to remain positive publicly - by racing for Ferrari he is emulating his hero Michael Schumacher after all - but the honeymoon period is surely over now.

Vettel is not Alonso, but they share the qualities of elite champions: extreme drive, utter determination, and an unquenchable thirst for winning. That sort of character can only take defeat temporarily.

If Ferrari cannot shake its status as F1's perennial underachiever, how long before a man of Vettel's obvious talent and ambition decides, like Alonso before him, that he's had enough?

How long before his patience finally runs out?