Some key developments to look out for at Spanish Grand Prix

The Spanish Grand Prix, as the first European round of the world championship, is always a time of significant developments up and down the field, ...

The Spanish Grand Prix, as the first European round of the world championship, is always a time of significant developments up and down the field, which can change the pecking order in places. So what can we expect this weekend, as the teams bring their first significant upgrades of the season to Barcelona?

All F1 teams have aerodynamic departments which will be looking to add 1 "point" of downforce to the car each week in the wind tunnel and using computer CFD simulations. The rough rule of thumb is that three points of downforce is worth around 1/10th of a second in lap time.

So in three weeks of development you should gain 1/10th of a second, if everything is going well. This is why, if you take a wrong development path and lose time, you lose ground to the opposition. This is where the technical leaders, like Mercedes' Paddy Lowe and Ferrari's James Allison really earn their money, as they have to bet on the areas they believe will give the best results and deploy their resources and time on those. It's what Ross Brawn was always brilliant at.

It's a gamble you can't afford to get wrong too often in a competitive F1 situation. But the other thing to bear in mind is that the strike rate for good ideas that get taken to the production stage, is about 20%, in other words about 80% of research and development ideas don't get onto the car.

It has been around 8 weeks since the start of season, so teams will be looking at just under 3/10ths of aerodynamic gain from their Barcelona updates, if the majority of the effort in the tunnel has gone into this upgrade. Some teams do it more piecemeal, with smaller upgrades on a more consistent basis.

There will also be some engine development steps in Spain, with manufacturers looking to introduce an update with a few of the famous "tokens" being used to improve some of the six components of the power units. This year there are only four Power Units per driver permitted so this is a good time to move to an upgraded engine. Renault will have an updated engine looking at fixing some of the reliability issues it experienced with Red Bull and Toro Rosso. Daniel Ricciardo is already poised to collect a penalty for using a fifth engine due to failures in the opening rounds.

There have been murmurings that Mercedes has used much of its development resource on reliability at the possible expense of performance over the winter, with Ferrari engined cars now topping the Speed Trap and Ferrari winning in Malaysia, where advice on cooling may have been quite conservative. Perhaps Mercedes has been a little conservative overall, given that the only reason the works team failed to win every race last season was reliability and also the reduction to four PUs per driver this year.

So it will be interesting to see whether they let the brake off a little there now, to chase performance again to stay ahead of Ferrari. One thing we have already seen, which is affecting race strategy and outcomes, is that whereas Mercedes engined teams are obliged to spend parts of the race in a more 'conservative' race mode, the Ferraris can run at a single more aggressive mode for the whole race. This is something Mercedes will have been addressing behind the scenes since the early races.

Ferrari had more tokens to use during the season than Mercedes, but not as many as Renault. Honda was awarded an average of the others' allocation and has the most ground to make up.

At the start of the season Renault had available 12 of the maximum 32 development tokens to use, Ferrari 10, Honda 9 and Mercedes 7. It is not known how many tokens Renault and Honda have used so far in the various new power units they have brought for their drivers in the first four races, but it is known that Ferrari and Sauber its customer were still on their first engine as of Bahrain Grand Prix as were the four Mercedes-powered teams. So one would expect a development step soon on Power Unit two for them, for Spain or Monaco.

Key areas of concern - Brakes

It is very apparent that the brakes are close to the limit of capability now and this has been an area of concern for several teams already this season, therefore much effort will have gone into improved cooling and aerodynamic solutions around the brakes. Why is this happening? It's quite simple; the cars are heavier and they are travelling much more quickly on the straights than in recent years.

With the 13" rims and brake disc thickness controlled by regulation, we are close to the limit now and with forthcoming races like Monaco and especially Canada in mind, teams will have been working on upgrades. Mercedes have had some concerns in the opening races and several teams have had quite serious problems with brakes, including Red Bull, which is unusual for them as it's not been an area of concern in the past.

Key area of need - rear wing

Since Peter Prodromou and his team at the time at Red Bull mastered the multi element cascade front wing, the efficiency of the front of the cars has been very high, but there is still more to come and we will see development here, especially as this is only year two of the narrower front wing regulation.

However everyone is struggling to get a similar result at the back of the car, since the banning of the blown diffuser and the removal of the lower beam wing. Also the reduction in size of the main element of the rear wing exacerbated the problem. Working this lower beam and floor area in particular was Red Bull's ace trick between 2010 and 2013 and when the rules change in 2014 it was a huge blow that they haven't recovered from. Add in the woes of engine partner Renault and that's a big part of why they are where they are now.

Where the magic happened: 2013 rear wing assembly, note lower beam

Mercedes did well last year on rear end downforce, but even they need more.

One of the restrictions is that weight distribution front to rear is now fixed by regulation; teams would dearly love to have a more forward distribution to better exploit the efficiency of the front wings around now. But the FIA technical regulations say that "The weight applied on the front and rear wheels must not be less than 319kg and 376kg respectively, so a bias towards the rear.

Ferrari has added a lot of downforce compared to last season, but could certainly do with more. They still have a margin back from the Mercedes in single lap qualifying pace, which is the key battleground, as their race pace is good and they are able to look after the rear tyres better than Mercedes in some situations.

Williams also needs more downforce, particularly at the rear and much effort will have gone in there to make up the disappointingly large gap that they find themselves behind Ferrari. But they have a comfortable margin over their pursuers, Red Bull and Lotus, so they will be in a race of their own for the time being, it seems.

Force India has made an expensive step up to the Toyota wind tunnel and should start to see the fruits of that in a B spec car which is due in Austria. Force India tends to have lopsided seasons; either strong at the start and less so at the end, or the other way around.

Sauber took some useful early points from a fast, reliable car with an improved Ferrari engine but is likely to slip back behind Toro Rosso and McLaren Honda in the development race over the coming months, providing those two teams also get the promised gains from their engine supplier.