Cyril Abiteboul has urged Formula 1's Strategy Group not to go "conservative" when they sit down later this month to discuss the 2017 regulations.
Last year Formula 1 had promised fans that cars would be louder, faster and look more aggressive in the future.
However already there has been some backtracking over that as concerns have been raised about whether the Pirelli tyres could cope with the added loads.
F1's Strategy Group is scheduled to meet later this month to put together the final proposal and Abiteboul fears they go opt for a "more conservative solution" instead of the radical changes initially proposed.
"We are not part of the F1 Strategy Group, so we are not part of those discussions," the Renault F1 chief told ESPNF1.
"What do we think will happen? If I'm clear, I don't know. I'm just a bit afraid that we go to a more conservative solution and try to avoid any change because basically people are afraid of doing a mistake.
"There is some feelings that Formula One is threatened by a number of things and we are afraid of making the wrong decision, so we prefer to make no decision. I think actually making no decision can be a bad decision in itself.
"We would like to see ambition, we would like to see people being daring and change. If we f— up we can always deal with that."
He added: "There are a number of things that I've seen that we should try, for instance changing the weekend format, because if it doesn't work out we can always go back to the old system.
"There are a number of things that are good – making the car go quicker, trying to make sure the drivers don't have to preserve the tyres so much."