The FIA has dropped a requirement that Formula One engines should last for three successive races this coming season.
World motorsport's governing body kept the requirement in place last month when it announced that, as part of efforts to cut costs, each driver could use no more than eight engines in 2009.
However, Article 28.4 of the 2009 sporting regulations, posted on the FIA's website this week, makes no mention of engines having to be used in sequence.
"Each driver may use no more than eight engines during a championship season," the amended regulations declare.
"Should a driver use more than eight engines, he will drop 10 places on the starting grid at any event during which an additional engine is used."
An FIA spokesman confirmed the new rule would allow drivers to use their eight engines in whatever sequence they wished.
But a Ferrari spokesman said that some of the details concerning the application of penalties had still to be clarified.
In another change, Friday's practice sessions - which have assumed heightened importance now that in-season testing has been banned - also fall within the eight-engine rule.
Assuming they have not yet used their full quota, drivers will therefore not be penalised if they suffer an engine failure in practice either on Friday or Saturday morning.
However, should a driver suffer an engine failure during Saturday qualifying, parc ferme rules mean they will receive a grid penalty.
Drivers had to make their engines last for two races in a row last season or incur a 10-place penalty, although they were allowed one 'free' change.
The requirement for gearboxes to last four successive races remains in force.
There are 17 races this season, starting in Australia on March 29.
TheStig