Mercedes boss Toto Wolff has defended his team against critics who say that their dominance of Formula One has damaged the sport, insisting they cannot take a "holistic approach" to protecting the spectacle.

The Silver Arrows have won each of the last four constructors' championships, with Lewis Hamilton taking three drivers' titles and Nico Rosberg winning the other.

Accusations of predictability have been used as a stick with which to beat F1 over recent years and the big question ahead of every season has been whether anybody can challenge the might of Mercedes.

A meaningful rival has failed to materialise since Mercedes ended a period of Red Bull control in 2014, but Wolff insists his team's objective is to win and nothing more.

"If you look from outside, does a long-term dominance of the team damage the spectacle? Yes, it does," he said at the launch of the team's 2018 car. 

"We've seen it with the success of Ferrari in the 2000s and Red Bull a couple of years ago and then Mercedes.

"I think the most healthy situation for Formula One is a very competitive environment where multiple teams are able to win and the championship goes down to the wire at the final race.

"These are clearly the ingredients it needs. But it's not the objective of this group here today.

"We try to optimise what we are able to deliver and we can't, from where we sit, have a holistic approach to the global spectacle."

Wolff does, however, believe there are a number of teams who could potentially disrupt the status quo in 2018.

"If you'd have asked us last year, we'd have said Red Bull will be the main contender, and it happened to be Ferrari," he said.

"So I think it's very dangerous before the season has started to reduce the number of potential competitors to one or two teams.

"You need to take everybody seriously. Ferrari is very strong, Red Bull is very strong, I'm curious to see how McLaren is going to perform, the step up of the works team of Renault and Williams has gone quite radical.

"So I think you need to keep the mindset of taking everybody seriously at this stage."