Mercedes engine now only ahead of Honda - Perez

Mercedes' power advantage in Formula 1 has been wiped away by a "massive step forwards" from Ferrari and Renault since last season, reckons Sergio Perez.

Sergio Perez, Sahara Force India F1 VJM10

Sergio Perez, Sahara Force India F1 walks the track

Sebastian Vettel, Ferrari SF70H, Kimi Raikkonen, Ferrari SF70H

Sergio Perez, Force India VJM10, Esteban Ocon, Force India VJM10

While Mercedes emerged as benchmark power unit when the new turbo hybrid regulations came into force in 2014, its rivals had been able to close up the gap steadily.

But it is the step forward that Ferrari and Renault have made over the winter that has left Perez convinced that the Mercedes engines which power his Force India team are no longer clear of the opposition.

"I definitely think that Ferrari is at the same level as Mercedes, and Renault is more or less there," explained the Mexican. "We only have the advantage over Honda."

In the past, Force India has benefited from the Mercedes engine edge but in a season where power is more important – because of the faster cornering and higher drag from cars – being on equal terms makes his team's midfield battle even more intense.

"This year, with these cars, the engines are much more important than in the past, because the amount of time you spent at full throttle was a lot less [last year] and the amount [of energy] you recovered was also a lot less," added Perez.

"Definitely Ferrari and Renault have done a massive step forwards to catch Mercedes."

Sochi hope

Although Force India is currently in fourth place in the constructors' championship thanks to double points finishes in the first three races, the team believes it needs to make improvements to lift the overall pace of its car.

And although Bahrain was a difficult weekend – with Perez eliminated in Q1 – he thinks that this weekend's Russian Grand Prix will deliver improved fortunes.

He thinks the Sakhir layout, which requires good rear grip and a stable car for braking, exposed the weaknesses in the Force India chassis.

"I think this track should be a bit better for us," he said. "Bahrain really exposed all of our issues in one go.

"It was also a very tricky weekend up until qualifying with all the issues that we had personally with the car, and I think Bahrain was always going to be a hard race for us, given the track layout.

"It was probably one of the hardest races for us, so I think here we can be a bit more competitive and closer to where we should be."