Although Force India has finished with both cars in the points in all three races in 2017, the team has been disappointed with the pace of the Mercedes-powered VJM10.

Fernley blames a windtunnel-to-track correlation problem for the car's weakness in slow and medium speed corners, but is confident the team can correct with the upgrade to be introduced in Spain next month.

"We know exactly what it is, Andy [Green, technical director] and the team have determined that there's a correlation issue, we knew that in Barcelona testing," said Fernley.

"The effects were identified, [solutions] put in place and it's just a production process and it will hopefully bolt on in Barcelona and we can go toe-to-toe again as opposed to having to defend.

"It's related to our aero platform. The problem is that you pick one bit up and it affects different areas and you've got to go back through it, correct it and then produce the new part for it. The new floors and things will be available for Barcelona."

When pressed on the exact reasons for the problem, Fernley confirmed that the car was suffering from stalling.

He is also hopeful that Force India can further reduce the problem for the Russian Grand Prix based on work done in the post-Bahrain GP test.

"Yes, there's a whole number of other issues as well, it's a major upgrade, but part of that upgrade will also be the correcting of some of the issues that we had or we identified in Barcelona [testing]," said Fernley.

"The drivers say they have instability and it's stalling and [downforce is] coming in and out and it's slow to medium corners.

"Bahrain highlighted it particularly, Russia will probably do the same but we can do some testing.

"We won't solve it, but we might be able to mitigate it."

Gary Anderson's view

Force India is a team that is struggling for consistency, which is a problem because that's what you need to build on. If every session is a new adventure, it means you just don't go forward.

An airflow separation problem would explain a lot. This can come from a multitude of things and everyone talks now about airflow structures around the car. Basically, the car must work the airflow as one; gone are the days of developing one area in isolation, putting them all together and the car working.

Any component that is against the ground works in what is called 'ground effect'. The front wing, the front wing endplates, the bargeboard area, the leading edge of the underfloor and the diffuser are all areas that are highly critical to ground effect.

It is always difficult to get complete windtunnel-to-track correlation, basically because the roughness of the track surface, and especially the track temperature, can affect airflow separation.

It can also come from other aerodynamic components ‘stalling' and affecting the airflow to one of these critical ground effect components. It can be really tough to find where the problem is being instigated, otherwise it wouldn't be there in the first place.

In the short term, if you can isolate the problem it's OK to put a bandage on it. But in the long term, for overall performance, it is better to fix it at source. This is what Force India seems to expect to happen with the Spain upgrade.