It's El Nano's home race and there'll be a lot of Spanish and Asturian flags flying, but what else...
1.Everyone will have major updates
It's been almost two months since the season started and now is the time that teams start bringing bits they've copied off other cars, as Mercedes' Paddy Lowe explained.
"Aside from being the first European race of the season, Barcelona is classically seen as the first big milestone for upgrades from the teams and we can expect to see quite a range of developments throughout the pit lane. The circuit itself is highly demanding on the cars: arguably requiring the best combination of power, handling and aerodynamics seen during the entire season. It's often said that a car which performs well in Barcelona will be a great car for the season, so we're looking forward to seeing where we stand relative to the competition."
2.Sauber have a new lightweight car
Sauber have been battling with a car that's been 20kgs too heavy for the opening races and seen themselves slump to the back as the team most likely to be going out in Q1 along with Marussia and Caterham. But now they've got a new lightweight C33. They'll also have revised aero, a new engine cover, new side-pod fins and deflectors, as well as a number of other aerodynamic changes. They'll also be changing the engine software to improve power and boost efficiency.
And this kind of radical change is going to be replicated all the way down the pitlane.
3. Barcelona is a good indication of future results
As Paddy Lowe said, the Circuit de Catalunya gives the best test of the three combined elements that make an F1 car fast: power, handling and aerodynamics.
Paul Hembery, Pirelli motorsport director agrees: "A car that performs well in Barcelona should perform well everywhere. The same is true of the tyres, because the Spanish circuit is one of the most demanding circuits we race on all year. Long and fast corners such as Turn Three put a huge amount of energy into the tyres, as a result of which degradation is high.
"The track surface is also quite abrasive, and ambient temperatures can be high, which increase the workload on the tyres further. In the past we've seen up to four pit stops in Spain. With the changes we have made to the tyres this year, we would now hope to see no more than three for the majority of drivers."
4. It's the return of the motorhomes
Barcelona is also where the teams show off their new motorhomes, or rejoice in the warm familiarity of the old one. For Red Bull it's the return of the Energy Station or to some 'the fizzy drink Death Star'.
5. McLaren should be ready to deliver
McLaren have been making some very bullish noises of late about how they've worked out why they are not as fast as they thought they were going to be. Operatic diva Montseratt Caballe sang Barcelona and Barcelona - for the McLaren team - is where the fat lady has to start singing.
6. The weather is going to be Scorchio
Right now the weatherman says it's going to be full sun and around 24C for all three days, so we're not likely to see the full wets this race.
7. Mercedes won't be easing up the pressure
Mercedes boss Toto Wolff is keenly aware how good a job Red Bull can do and said ominously: "Our aim must be to increase the advantage we enjoyed at the last race in China. As a team, it is up to us to rise to that challenge: to take that relentless mentality to an even greater extent than those around us."
The much-admired Red Bull RB10 chassis should be at its perfect race track in Barcelona and so this could be the closest they come to dislodging Mercedes. However the W05 has shown itself to be very good on tyres, with Hamilton excelling in Shanghai. Barca is a tyre eater, so that could be the key.
8. Lewis wants pole
Doesn't he always. He would have got it in 2012 for McLaren if he hadn't been sent to the back of the grid because of a fuel misdemeanour. However last year it was team-mate Nico Rosberg who took pole and Lewis had a miserable race. Lewis said this week:
"What I'm really trying to focus on is those circuits where I am maybe weaker, or not as close to him (Rosberg)." This will be one of them.
It's also critical because Barcelona is a difficult place to overtake.
9.Lotus might score some points
They've been steadily improving race by race, and last time out Romain Grosjean put his E22 into Q3. Now with a "significant step" from Renault the team are anxious to start scoring. Pastor Maldonado scored his maiden victory here in 2012 so he's no slouch either.
10. Kimi should be closer to FernandoAlonso rarely lets his home fans down, whether in Barcelona or Valencia, but the man most hoping to make an improvement is team-mate Kimi Raikkonen who finished the Chinese race 50 seconds behind Alonso. Kimi's struggling with the way the F14T turns in to corners but Chassis Technical Director James Allison thinks he'll have it sorted soon. "Kimi has class written all over him," he told the Ferrari website, "and we know that within in a very short space of time, we will also be seeing the results on the track."
So definitely NOT a case of "Leave me alone I know what I'm doing"...