McLaren partner Honda gets extra engine for 2015 Formula 1 season

As part of a raft of regulation changes decided in Wednesday's Strategy Group meeting, the FIA said an extra power unit per driver will be granted for any new manufacturer entering the sport.

The FIA said "for the sake of fairness" the measure will apply retrospectively to Honda, which entered the sport with McLaren this year, for the 2015 season.

It comes after Alonso and Button were given 25-place grid penalties in Austria when they both exceeded their respective engine allocations by taking a fifth unit.

The rules divide the power unit into six elements - the internal-combusion engine, the MGU-K, the MGU-H, the turbocharger, the energy store and control electronics - that can be individually exchanged.

When a driver breaks into the first of their extra power units with the introduction of any one of those components, they are hit with a 10-place grid penalty with a five-place drop for the subsequent components of that power unit.

The pattern continues with each subsequent extra power unit, but now each McLaren driver will be able to introduce a complete set of components without penalty thanks to the rule change.

Meanwhile, the FIA added the price customer teams have to pay for an engine supply will be looked at as part of a wider tweak of the current engine formula.

Currently, customer teams are paying between £14-17million for the powertrains.

"Mandate has been given to the FIA and FOM to propose a comprehensive set of measures for power unit development and cost of supply," added the FIA in a statement.

"This will include full review of the token system, increase in race fuel allowance, limits of the usage of engine dynamometers etc."