The FIA's Head of Powertrain, Fabrice Lom, has explained the intricacies of Formula 1's revised engine regulations, which will be introduced at the start of the 2017 campaign.
The FIA last month rubber-stamped changes in four key areas: cost of supply, performance convergence, sound and obligation to supply.
During a press conference at the Spanish Grand Prix, Lom explained the details of the regulations and how the system intends to be operated.
"For the reduction in price for the teams, we first worked to reduce the cost, because we cannot ask the power unit manufacturers to reduce price without reducing cost," he said.
"So to reduce the cost, firstly in 2017 we will go down to four power units per driver per season, instead of five, whatever the number of grands prix.
"And in 2018 we will go down – and this is a big task for them – we will go down to three ICE, plus turbo, plus MGU-H and only two energy stores, control electronics and MGU-K. So it’s nearly 50% less parts, so it should reduce the cost by a nice amount.
"In addition to this we will have a discount for the price and there is an engagement from the power unit manufacturers to decrease by €1 million in 2017 compared to 2016 and by €4 million compared to 2016 from 2018 and onwards.
"So it gives discount for all the customer teams of around €28m per year, which is not something negligible I think."
Lom explained that a ballot system could be introduced regarding the obligation to supply.
"The idea was to have no teams that is not able to have access to a power unit," he explained.
"This was a big part of the discussion because we also don’t want people to be able to play with that and to change from one power unit to another from one year to another in order to have the best one.
"So there is a quite complex system in place, but the basic [premise] is that if you are a team with no offer, so nobody is offering you a power unit, you can ask the FIA to have one and there is a system of ballots.
"So we will take the power unit that has the smallest number of customers. If there is only one, this will be the one that will be required to give the power unit.
"If there is more than one there will be a ballot between the two to decide which one will supply, and there is a low price of €12m from 2018 for this supply."