F1 is planning to deliver cars that are up to five seconds per lap faster next year, as part of an effort to make it harder for drivers and to lift excitement levels.

But that speed leap has prompted concern from a number of leading stars, who reckon that a dramatic increase in downforce levels will make it almost impossible to follow other cars close enough to be able to overtake.

Lewis Hamilton is one who has spoken out several times about the changes, which he thinks are going to add nothing to the show.

"I think we need more mechanical grip and less aero wake coming off the back of the cars so we can get close and overtake," he said.

"Give us five seconds' worth of lap time from aero and nothing will change - we'll just be driving faster."

Mechanical grip

But F1 race director Charlie Whiting thinks such concerns are unfounded, because a lot of next year's speed increase is going to come from mechanical grip due to bigger tyres.

"We've had countless meetings with the technical directors of every team, and we have had a whole range of proposals from what appears to be a huge amount of downforce to a very low level of downforce," explained Whiting, about the process that the FIA has gone through.

"But it is all based on the premise that we will have a significant increase in mechanical grip. So what we have ended up, inevitably, is somewhere in the middle.

"It is incorrect to say that the anticipated lap time improvement will all come from downforce, because it simply shouldn't be."

He added: "The whole idea is that half of that will come from mechanical grip, and the other half will come from aerodynamic downforce.

"One of the things that we have been talking all along is the fact that we must not make it more difficult to follow another car, and that has been one of the underlying principles. So, we've done I believe the best we can, given we have to take everyone's views in to account."

Overtaking mandate

FIA president Jean Todt made it clear over the Bahrain weekend that one of the key considerations for the 2017 rules package was that overtaking was not ignored.

"The mandate is how to make F1 show that it is the pinnacle of motorsport, how to make cars quicker, more spectacular and facilitate overtaking but remaining inside some decent budget," he said. "That is the mandate."

Pirelli briefing

One important component of the 2017 package is that Pirelli delivers the right kind of tyres that will allow the cars to perform better.

Whiting said that within the next few days, the FIA should be ready to provide F1's tyre supplier with a briefing document explaining exactly what type of tyre characteristics is required.

"We have discussed it at length with Pirelli," he said. "We had a meeting in Milan with Pirelli in the beginning of February and we were asked to present them with the targets that we believe Pirelli should achieve during the course of their new contract.

"We are literally ready to supply Pirelli with a set of targets that we feel they need to achieve during the course of their renewed contract. It is all ongoing stuff."