Force India: Barcelona upgrade no cure-all for 2018 car

After a difficult start to the season, Force India bounced back with a third place for Sergio Perez in Baku, but Fernley admits that the unusual high-speed layout of the track and the circumstances of the race played a role.

He believes the team still has to prove that it has fully resolved the correlation issues between wind tunnel and track that have troubled it thus far.

The team has traced some of its issues to the sidepod design.

"I think feet on the ground, we've still got a little way to go," Fernley told Motorsport.com. "We're not quite there yet.

"We've not addressed all the correlation issues that we had in Melbourne, but we're on the way to it.

"I think we probably could and should have got points in Bahrain and Shanghai, and obviously we had first-lap incidents. In Baku we had a fantastic bonus which makes up for those.

"We shall still have some issues in Barcelona, it's not going to be all plain sailing."

Chief Operating Officer Otmar Szafnauer agreed that the value of the Barcelona package was still to be determined, and he admitted that it takes time for a team of Force India's size to get upgrades onto the car.

"I don't know how much of the problem we'll fix with the stuff coming in Barcelona," Szafnauer told Motorsport.com.

"Because there is a lag between finding a problem and actually getting the stuff onto the car. But it should be floor and sidepod, and it should be good."

Szafnauer conceded that the track doesn't always back up the results obtained in R&D.

"You always bring updates that the tunnel and CFD have given you an indication are going
to be better than what you have now, and by a significant amount. But that's not reality.

"So you've got to bolt them to the car, see if it correlates, if it doesn't, you have to understand why. Sometimes it doesn't because you haven't optimised the car on track yet. You have to spend time with those parts, just optimising around them.

"Sometimes it doesn't correlate, the tunnel tells you you should be doing one thing and reality isn't quite like that, so you've got to figure out what it is.

"I remember Mercedes one year were saying they stopped developing their car with six races left, so they put nothing more on their car.

"And it just got faster and faster and faster, because they had a stable platform that they understood and they could work on making that platform go faster.

"If you're changing stuff all the time that's not good either, because it mixes up your understanding."

Baku podium finisher Perez, for his part, has clearly put a lot of faith in the Barcelona package.

"In [Barcelona], we have a very important challenge," said the Mexican. "Barcelona is where really the car is. You show all of your potential there.

"It will be very interesting to see where we are. I believe that we are making good progress."