The European season of the 2018 Formula One championship is about to begin in Spain. The teams arrive to the Catalunya circuit with upgrades, updates and plenty of questions about the competitive order. From warring team-mates, to a returning Pole and an under-performing Frenchman, here are your reasons to watch all the F1 action this weekend!

Are Mercedes back on form?

The early stages of the European season usually sees the emergence of the year’s true title contenders. Mercedes took their first win of the season with a lucky Lewis Hamilton in Baku two weeks ago, while Sebastian Vettel was also in with a genuine shot of victory until he ruined his chances with a lock-up into the first turn just a few laps before the end of the race.

Pre-season testing seems like a long, long time ago now, but, if you can remember that far back, Mercedes were hotly tipped to be the runaway favourites heading into the season after their performance around this track. Will the pace they had in the winter testing translate into impressive race pace this weekend?

The odds are in Mercedes’ favour, with them having taken every pole at this track since the 2013 season and winning three of the last four Spanish Grands Prix. Past form certainly doesn’t guarantee anything this season, though. Vettel will be hungry to make up for his lost Azerbaijan points. The Circuit de Barcelona-Catalunya is one of only four tracks on the current calendar where Vettel hasn’t yet taken a pole position.

So will the first round of the European season favour Lewis Hamilton or Sebastian Vettel? Or will the other Mercedes driver emerge as a real front-runner for 2018?

Some good fortune for Bottas?

Valtteri Bottas has had a great start to the season – though his results haven’t fully reflected that. Had the order stayed the same after Vettel’s mistake on the final Safety Car restart in Azerbaijan, the Finnish driver would be leading the championship. He’s come close to taking the win for three races in a row now and, without the slip-up in Qualifying in Melbourne, he could be a lot closer to Hamilton and Vettel than the current points tallies show. Can Bottas maintain the momentum this weekend and put himself in a position to challenge the pair of four-time World Champions at the top of the standings?

What will the atmosphere be like at Red Bull?

After their tangle in Azerbaijan, what will the mood be like between the drivers in the Red Bull camp? Is all swept under the rug or will we see a change in the dynamic between Daniel Ricciardo and Max Verstappen?

More importantly, the pair’s coming together cost the team a large haul of points, and they now sit with half of the points which Mercedes have. The duo need to worry less about each other and start amassing points quickly if they’re to have any shot at the title this year. Verstappen and Ricciardo each have one podium at this track – Ricciardo made his first ‘real’ podium appearance here in 2014, while Max Verstappen also made his first ever appearance on the rostrum with his first win here in 2016. Can either of them make it into the top three again on Sunday?

Woe-man Grosjean

Things aren’t going too well for Romain Grosjean so far in 2018. The Haas car seems to have good pace, but the Frenchman is yet to score a point this season. A pit-stop error put an end to a strong charge to fifth for Romain in Australia, and since then everything seems to have gone downhill. He qualified down in sixteenth in Bahrain and finished outside of the points, then qualified in tenth in China but had his race ruined by the timing of the Safety Car, finishing in a lowly seventeenth. Baku was definitely a weekend to forget as he qualified last, failing to set a time as he came to a halt down an escape road. Then, in the Grand Prix, the Haas driver embarrassingly crashed behind the Safety Car. Only Sirotkin is behind him in the championship. If both score points, it’ll be the first time every driver competing in a season of F1 has scored a point. Can Romain catch a break this weekend?

Kubica Returns!

Sadly not to a race seat, but we’ll be seeing Robert Kubica taking part in an F1 weekend for the first time since the 2010 Abu Dhabi Grand Prix. He’ll be driving in the first Free Practice session on Friday, taking Sergey Sirotkin’s seat. Kubica announced that he’d be partaking in three practice sessions throughout the year at Williams’ 2018 launch event back in February. He’ll be making further appearances in Austria and Abu Dhabi. How will the Polish driver’s times compare to the full-time race driver?

Updates and Upgrades

The beginning of the European season traditionally sees the teams bringing their first major updates and upgrades of the season. Most anticipated are McLaren and Force India’s upgrade packages. Some are referring to the car which McLaren will bring to Barcelona as a ‘B-spec car’. A rumoured ‘radical’ new nose is set to be the main talking point. Expect local hero Fernando Alonso to take a lot of the limelight this weekend, with his home event coming off the back of his impressive win on his World Endurance Championship début at Spa.

Vijay Mallya has said that Force India’s podium in Baku might be the ‘turning point’ of the season for them. The team appeared to be struggling in the first three rounds, having only scored one point, but with a podium now under their belt they’re beginning to climb back up the table. Currently in sixth place, the teams needs to work fast to make up the twenty point gap to their nearest competitors Renault.

Will the upgrades see a change in the competitive order in the midfield pack?

The 2018 Spanish Grand Prix begins at 2:10pm BST on Sunday. In the UK, the race is exclusively live on Sky Sports F1.