Kimi Raikkonen suspects that Mercedes’ ability to turn up its engines for qualifying and certain phases of the races could be making all the difference in their fight this year.

Ferrari was able to threaten Mercedes in the early part of the campaign, but has since fallen away from the front and is now behind Red Bull in terms of out-and-out pace.

One key advantage that Mercedes is known to have is an extra boost it can get from engine settings in qualifying – and when needed in the race – which could be worth as much as three tenths of a second per lap.

That factor was one of the reasons why Raikkonen was pleading with his team to be allowed to run a better engine mode in his battle with Nico Rosberg at the Malaysian Grand Prix.

When asked if he felt engine modes was one of the biggest differences between Mercedes and Ferrari, Raikkonen explained: "It is only guessing, what they do or how much the difference is, but we have seen it before. In some race conditions or qualifying, they go faster. We all have GPS, so we can see what happens.

"We do our maximum and this is what we can do. We have to improve things, but this is nothing new. We have to make the car faster to be able to challenge the others. It is not something new, they have been faster than us most of the year, it is just areas we have to keep pushing and improving."

Raikkonen, who finished fourth in Malaysia after being barged out of the way by Rosberg, says that there is no particular vice with Ferrari's current car – it just lacks speed.

"We try to improve all the areas all the time," he said. "In qualifying, we are not as fast as Mercedes so it is hard to expect we will suddenly beat them in the race. But in race conditions, we are usually stronger.

"Handling wise it feels pretty good, we just need to go faster. There are not one or two places that have a big issue, and that is why we are not as fast as them. We need more grip, more horsepower, and go faster with everything. Our aim is improve all the areas.

"It is not easy to find those things, otherwise everyone would go as fast as the fastest guy all the time. It is ongoing process to improve these things. We are not the only team that is improving things. We keep working and pushing and improving and fighting each race.

"Once the season is over, then we start thinking of next year, and we try to find all the areas to improve."


Gallery: Mercedes dominance helped by engine modes - Raikkonen