Red Bull boss Dietrich Mateschitz has expressed his belief that Mercedes will dominate the 2015 season based on evidence from the first pre-season test last week.
Although they didn't set headline lap times, Mercedes impressed with the amount of laps that they did and it has been suggested that they are hiding their true pace as they focus on the car's reliability, which was their Achilles heel last year.
Mateschitz told reporters: "Mercedes are still in front and it looks like there will be no change to their dominance."
"Mercedes have a more powerful engine than Red Bull, who are supplied by Renault, and Mateschitz believes that if that can be reduced then his team could compete with them this season.
"If Renault can reduce the gap [to Mercedes] to 40 or 50bhp then we should be in a good position to charge, provided we have a good car again. But I do not doubt this. To reduce the gap would be a success already."
Red Bull won four consecutive championships between 2010-2013.