Spanish GP: What you need to know

It's that time of the Formula 1 year again: the return to Europe, the Spanish GP, and the place where the sport's development war really begins in earnest.

Jenson Button, who makes his first appearance of 2019 on the Sky Sports F1 team this weekend, has described Barcelona as a perennial "pivotal moment in the F1 season".

When's the Spanish GP on Sky?

Can Ferrari bounce back and halt Mercedes' charge? Find out this weekend at the Spanish GP, live only on Sky Sports F1.

Expert analyst Mark Hughes, meanwhile, reckons the weekend could see "the possible re-aligning of the competitive orders seen in the first four flyaway races".

After four Mercedes race-day clean sweeps, what is certain is that Spain marks a crucial weekend for Ferrari and Red Bull - who, armed with car upgrades, really need to start turning the early championship tide.

What are the teams and drivers saying?

Toto Wolff, Mercedes: "The results seem to paint a relatively clear picture, but the truth is that they're too flattering. The performance has fluctuated in the first four races. We had the fastest car in Australia and China, but we won in Bahrain thanks to our reliability when we were on the back foot in terms of speed. And while our race pace looked good in Azerbaijan, we were never able to build a truly comfortable gap to our rivals. So there is no complacency about our situation because we know that it's not truly representative of the balance of power this season so far."

Cyril Abiteboul, Renault: "The start of the European segment of the 2019 Formula 1 season is an opportunity for us to reset. Overall, it's been a tough start to the year and the Azerbaijan Grand Prix capped off a run of results that fell short of our expectations. We know we are capable of much more and we need to target clean weekends and races to make the most of our potential."

Get Sky Sports F1 for £10

Sky Sports F1 the Home of Live and Exclusive F1 is available for just £10 a month

Mattia Binotto, Ferrari: "We are currently behind in the championship and we have to catch up, which we know means that our development work will be the key to this season. Having brought a new aerodynamic package to Baku, we will also bring some developments in this area to Barcelona. On top of that, we will have a new power unit that we are introducing ahead of schedule, as the second specification was due to be brought to Canada."

Guenther Steiner, Haas: "We're bringing our first upgrades of the year. A lot of parts on the car will change - the front wing, the floor and a lot of the smaller parts, like mirrors. It's a quite significant upgrade."

Carlos Sainz, McLaren: "I'm so excited for my home race. It's always such a special occasion and I can't wait to see all the fans in my grandstand, I'm looking forward to seeing it in full papaya!"

What's coming up on Sky F1 and when's the race?

British F1 legend Jenson Button joins the team for the first time this season to provide analysis and insight during the weekend.

The 2009 world champion will be sitting down with current championship leader Valtteri Bottas for an interview for Sunday's race show, while Button will also be starting a look back at his unforgettable title-winning year of 10 years ago at a Barcelona circuit that had special significance for Brawn GP.

We'll have part one of a special 'How to Drive' series with Bottas and Anthony Davidson, while we'll also be running the rule over the car upgrades being introduced this weekend and the formbook so far in 2019. And that's just a start for Sky F1 at Barcelona!

Sunday's race starts at 2.10pm with build-up from 12.30pm.

Have your say: Who is Hamilton's big 2019 rival?

Who's topping the championships?

While a Mercedes driver is yet to be headed on a 2019 podium, it's Valtteri Bottas' fastest lap bonus point from Melbourne which is keeping him clear of Lewis Hamilton.

Click here for the full championship rundowns

Who won Barcelona's winter war?

Winter Testing is Winter Testing but, for the record, here's how F1's 10 teams fared on the combined timesheet at the Circuit de Catalunya back in February and March. How Ferrari would love a repeat...

Quickfire stats

• In 2018, Lewis Hamilton became the first repeat winner of the Spanish GP in a decade. The previous 10 races at Barcelona were won by 10 different drivers
• For the first time since 2002, Fernando Alonso does not feature in his country's grand prix. McLaren's Carlos Sainz is the sole Spanish representative this weekend
• The last non-Mercedes pole position was achieved by Pastor Maldonado with Williams in 2012
• Race lap record: 1:18.441 (Daniel Ricciardo, Red Bull, 2018)
• Ultimate lap record: 1:16.173 (Lewis Hamilton, Mercedes, 2018 Qualifying)

Sky Sports F1 is the home of live and exclusive F1 - and new and existing customers in the UK can now get the channel for just £10 extra a month, our best-ever offer. Find out more here to watch the 2019 season live