Sergio Perez is optimistic that Force India's B-spec VJM08 can be potent enough to allow it to chase down Red Bull Racing for fourth place in the F1 constructors' standings.

The car, which makes its competition debut at Force India's home race, the British Grand Prix, this weekend represents the team's first real development of the machine that was rushed into action after little pre-season testing, and the Mexican is confident that it will show a marked improvement over the original. F1 hopefuls Esteban Ocon and Pascal Wehrlein gave the VJM08B a decent work-out in last week's Red Bull Ring group test, and Perez is keen to put into action at Silverstone.

"I'm definitely [looking forward to it]," he admitted, "I think the whole team has been waiting so much for this upgrade - it's basically the first upgrade for the whole year. It's nice at this time to look back and see what we have achieved as a team, knowing where we were two or three months ago. Now everyone forgets that we did two days of testing before the first race, that our car was in a hurry to make the first race, and now we have fifth [place] in the constructors', plenty of points in the drivers' championship, and plenty to come, so I'm really optimistic."

Although he didn't drive the car in Austria - along with fellow race driver Nico Hulkenberg - Perez said that the feedback and performance of the two young reserves engendered confidence going forward.

"In Austria, we didn't have the full spec, so it didn't really matter and didn't make much sense to have both drivers, or any race driver, doing the test," he reasoned, "However, we are all pretty optimistic as, when we saw the numbers, it looked quite promising. But, at the same time, we are being realistic and anyone in the paddock will tell you that an upgrade isn't simply putting it on the car and getting on with it - it needs some processes, some work to understand how to take the maximum out of it. Hopefully, tomorrow, we can get plenty of mileage to move on and see where we are. We need plenty of mileage on both cars to understand the changes.

"Basically, the limitations of the [old] car have been in the rear end, which has been quite weak - very weak, I would say. We expect to improve that phase of the corner, the entry and how you can lean on the car. By improving the entry, to me, you can really improve as everything comes more together.

"To bring more harmony into the car, to get the most out of it, this year so far has been really difficult and the car has been really difficult in races. Now, if we can have a bit better pace, it will come all together, better tyre degradation and so on, so there are plenty of things to look forward to as you don't just improve your pure lap time, you improve so many things that you will see a benefit in a race weekend."

Joking that the media may not recognise the VJM08 such is its makeover, Perez picked out two existing rivals as the remaining the biggest threat to Force India's fifth place in the points - before suggesting that the Silverstone-based team could set its own sights on something better.

"With people bringing upgrades at every race, it really depends where you look, but Toro Rosso and Lotus will be quite strong around here and should be our target to beat," he confirmed, "I'm a bit surprised by Lotus because, when we see all the simulations, they seem to be half a second a lap quicker than us but, for some reason, some reliability issues and so on, they haven't been able to unlock their full potential, so I think they are a big threat.

"Toro Rosso has a mega car and I think, when we have some downforce circuits, like here, they should be very strong.

"However, I think our target should be to chase Red Bull. If the upgrade goes well, and everything goes well with this car, then we should aim for them definitely."