Mercedes still has upper hand in F1, Red Bull's Verstappen believes

Despite a dramatic overhaul of F1's technical regulations for 2017, Mercedes showed in Barcelona this week that it has not lost any of its strengths.

In particular, it appears to have made a big jump with its power unit, which could help it keep the advantage it has held since turbo-hybrid V6s were introduced in 2014.

Red Bull went into testing considered the team most likely to threaten Mercedes, but its season ultimately rests on progress engine partner Renault can make.

While the 0.3 seconds per lap improvement Renault is targeting for the start of the season may not be enough to haul it up with Mercedes, Verstappen hopes steps planned later in the campaign will allow it to do so.

"For sure they still will have an advantage over us in the beginning of the season, power-wise," Verstappen said.

"But I think we are definitely catching up."

Red Bull itself had a fairly low key four days at Barcelona, focusing on reliability running rather than trying to go for headline times.

Verstappen said he was pretty calm about where things are, with teams set to bring updates for the next test starting on Tuesday.

"The most important thing for us was trying and make mileage and seeing if all the parts were holding on," he said.

"I think everything has been behaving pretty well.

"We've done quite a bit of mileage and also for me to get used to the car and also the whole team to understand the new type of car.

"I think we did a good job."

When asked if any other team had surprised him, Verstappen replied: "No, I don't think there were massive surprises.

"It's all within reach. It's too early to look to other teams. We were just doing our programme and haven't looked at others."