Toro Rosso close to deal for 2015-spec Ferrari F1 engines

Both Red Bull-owned teams are without a power supply for 2016 after requesting to end their deals with Renault at the end of this season - although talks have reopened between the senior Red Bull team and the French manufacturer.

Last month, Red Bull boss Christian Horner said Toro Rosso's situation was more critical than his own team's as work on the 2016 car builds accelerate.

Toro Rosso and Ferrari have started talks regarding a supply, which would ideally grant the former the latest specification unit.

But it is understood a 2015-spec is more likely and this would be accepted to get a deal over the line and reignite a partnership that previously ran between 2007 and 2013.

Manor was allowed to use year-old Ferrari engines this season after it exploited a loophole in the regulations that required only concessionary permission to use such units.

Appendix 4 of the technical regulations was tightened with each manufacturer only allowed to supply one specification of a homologated power unit in any calendar year.

But a proposal was drafted to allow the use of older-spec engines, subject to the approval by the FIA on a case-by-case basis, at the Power Unit Working Group meeting earlier this year.

This was then discussed at a meeting of the technical directors in August, where all were in favour of the proposal.

The idea will be on the agenda at the next F1 Commission meeting, which the FIA anticipates will be within the coming weeks.

Should the commission approve the proposal, it will go through to the World Motor Sport Council, which meets in December, for ratification.