McLaren Formula One CEO Martin Whitmarsh says teams are still seeking final clarification over the new engine rules for 2009, amid minor confusion about how the new power unit regulations are going to work.
The FIA announced in December as part of a new raft of cost-cutting measures that teams would be limited to a maximum of eight engines per season - although it explicitly stated that a previous agreement for power units to last three races would still remain in force.
However, the new F1 sporting regulations published this week suggest that the three-race requirement has been dropped.
Article 28.4a states: "Each driver may use no more than eight engines during a championship season. Should a driver use more than eight engines he will drop ten places on the starting grid at any event during which an extra engine is used."
Whitmarsh has confirmed that his team understand the three-race requirement has now gone, so engines do not have to be used consecutively, but he is not clear on how penalties are applied once teams have used up their eight engines.
Furthermore, the rules do not appear to state what happens if teams use replacement drivers over the course of the campaign.
Speaking to autosport.com about the engine rules situation, Whitmarsh said: "There is still some (confusion), because the regulations were accelerated out, I think some points have to be clarified.
"One of the points that isn't 100 per cent clear in the regulations is if you use your ninth engine do you get a penalty once, or every time you use the ninth engine? Logically, and it's everyone's belief that you get the penalty once, but it isn't explicitly clear in the regulations at the moment. There are a number of things that need to be clarified."
Whitmarsh said he was sure, however, that the only stipulation on teams was for them to use the eight engines - and it was up to them how they were rolled out.
"The race drivers have eight engines. It has changed also in that the regulations previously that limited engine life, or controlled engine life, were for Saturday and Sunday. The eight engines (rule) is for the race event and that spans Friday as well.
"So on the one hand, you've got the dilemma of severely limited testing, limited to zero between the first and last race, and the desire to conserve the eight engines to have as much of their life and performance potential available for the races and yet still you want to test on Friday.
"That's quite an interesting challenge, and that's life isn't it? You have a finite resource in most things in life and you have to use them to best effect, Just to be clear, the sporting regulations as published are that the race driver has eight engines and if he can make one last for all the races he can use the other seven on Fridays, but that's an unlikely outcome obviously."
He added: "You still have parc ferme so if it goes bang on a Friday or a Saturday morning, provided you are still within your eight engines you are not penalised. Once you start qualifying you come under not the engine limitation but parc ferme, and under parc ferme regulations if you change an engine you will go to the back of the grid."