Development during the season and year-old engines permitted in 2016
The saga around the engine rules for next season has apparently found a happy ending: the power units will not be frozen for the season, and year-old engines can be used if necessary.

As teams in the paddock are in full preparation for next season, the news is picking up pace at this end of the season. On Wednesday, catching everyone off guard, if not by surprise, the FIA refused to allow an engine supplier to provide a Power Unit from the previous year to any team: Toro Rosso, which is counting on a 2015 Ferrari V6 for next season, did not necessarily view such a decision favorably.
The Faenza team will be relieved by the decisions made by the FIA and the four F1 engine manufacturers during a very constructive meeting. The use of 2015 V6 engines in 2016 will thus be allowed. Each side should benefit: the engine manufacturers should be able to amortize their development costs over a longer period, while the smaller teams will be able to obtain engines at a lower cost.
Regarding engine development for next season, it has also been decided that in-season development will be allowed. Originally, let’s recall that all power units were supposed to be frozen before the first Grand Prix in Australia. Renault and Honda, lagging behind their competitors, will have some room to breathe. Since good news never comes alone, 32 development tokens can be used during next season, instead of the initially planned 25.
Through this series of decisions, the FIA, like the four engine manufacturers, are clearly betting on a field with tighter performance for next season. Mercedes, which still dominates the paddock, would have understood that too strong a dominance on its part would not be in the interest of the discipline.
Finally, Bernie Ecclestone’s idea to return to V8s, for cost and noise reasons, was rejected by the four engine manufacturers.