Although Mercedes are running away with this year's titles, Sergio Perez believes it is Red Bull Racing who have the "best car" on the grid.
Mercedes have dominated the start of this year's Championship, taking four wins from four races, while Red Bull have had to overcome some teething problems with their Renault V6 engine.
The reigning World Champions, though, has begun to make inroads, prompting Perez to predict that they will soon close the gap.
"We have seen in the past that the season is so long and four races is nothing," said the Force India driver.
"They [Mercedes] are quite a way ahead and I believe they have a big gap to anyone else, but I think Ferrari and Red Bull are going to close quite a lot the gap.
"I believe Red Bull has the best car, in my opinion they have the best car on the grid.
"[Mercedes] will be very strong throughout the season and the team to beat, but there can be some surprises during the year."
As for his own Force India team, Perez believes they are at the front of the field fight.
"I think we are not far off Williams, but McLaren for some reason have struggled quite a lot after the first race, which I struggle to understand why," he told ESPNF1.
"They looked very competitive in the first race, but for some reason they haven't been any more competitive. In Bahrain they were a little bit competitive, but other than that they are not at the moment.
"We know they are a good team, so hopefully they don't come back!"
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