Sebastian Vettel has called for F1 to reduce the cost of the power units and adopt more 'normally aspirated' engines in an effort to improve the racing, even though his team Ferrari vetoed such a move to have them introduced last year.

As one of the drivers to have co-signed a scathing letter from the Grand Prix Drivers' Association ahead of the Bahrain Grand Prix, four-time world champion Vettel has expressed a dislike for the current Formula 1 regulations as well.

Asked what rules he would like to see changed, Vettel believes the current power units, introduced in 2014, have become too expensive and it would be 'beneficial' to revert back to cheaper normally aspirated engines to aid the smaller teams.

"I personally think the current power unit regulations are too expensive and I think it would be beneficial for all the team and the whole sport to go to something normally aspirated."

However, Vettel's opinion doesn't resonate that of his Ferrari team, which vetoed a proposal that would see costs come down. However, the German says he cannot be accountable for his team's views.

"I stick to what I said, which is that these power units are too expensive. They have cost a lot of money already and they will keep costing a lot of money and think everything else that we have been trying to do with adaptations and changes of rules doesn't change the key problem.

"A lot of problems that we face now go back to the fact that it was just the wrong way to go. It's easy to raise your hand and admit that, but we are still stuck with what we have.

Even so, Vettel says his is an opinion that should be heard but not necessarily acted upon, emphasising that drivers shouldn't make the rules.

"I can't change the rules, but I think it's a good thing that you don't let one driver or one person make the rules, but equally we've addressed that the way it is currently set up is not the best either.

"It's clear that we drivers are not here to make the rules. In no sports does a sportsman make the rules, so that's clear and we don't want to be the ones who decide where the sport is going."