Ferrari changed some components of the power unit in Sebastian Vettel's car after the team had to install new elements in Kimi Räikkönen's car following the Finn's woes during the second practice session.
In 2017, teams' hands are tied more then ever in reliability terms because of the restrictions regarding the power units. Drivers are allowed to use only four power units throughout the whole season. Last year, the number of usable power units was limited in five.
Power units still consist of six different elements: internal combustion engine, turbocharger, control electronics (CE) , MGU-K, MGU-H and the battery pack (ES). The restrictions means one power unit has to complete ideally five GP weekends.
Tragically, Ferrari found problems with Räikkönen's ES and CE after the Friday practices of the Australian GP which urged the team to change them for the remainder of the event. The two Ferraris ran then smoothly on Saturday and Sunday and the power units behaved well over the course of the Chinese GP as well.
In Bahrain, however, the incredibly high ambient temperatures brought misfortune to Ferrari's power units. In the first free practice session, smoke spewed from Kimi Räikkönen's car which prompted the mechanics to change the internal combustion engine, the turbocharger and the MGU-H for the second practice outing. Vettel's CE was also replaced for the late running.
For precautionary reasons, Ferrari changed the turbocharger, the MGU-H and the ES in Vettel's car for the third and final practice.
The changes leave the drivers with only two fresh elements in many PU parts for the remainder of the long season. However, Ferrari is hopeful that some of the elements can be used at least in free practices later on in the season after the thorough inspection back in the Maranello-based factory.
Ferrari's early reliability woes indicate Sebastian Vettel and Kimi Räikkönen will be forced to introduce power units above the maximum allowed four ones which will trigger grid penalties.