Ferrari drivers Sebastian Vettel and Kimi Raikkonen have edged closer to Formula 1 grid penalties after taking their third new turbochargers of the season in Russia.
Drivers are limited to four components of each engine element for the season, with grid penalties handed out if they exceed that allocation.
This year, regulations have also been tweaked to prevent drivers from stockpiling engine components for the season to avoid penalties by making multiple changes on a single race weekend.
Ferrari's change comes after Raikkonen stopped out on track in first practice for the Bahrain Grand Prix a fortnight ago, with the team subsequently changing his turbo, MGU-H and internal combustion engine.
The team indicated in a statement it was relaxed about its turbo count at this stage of the season.
"Replacing a turbo, or any other component, does not necessarily mean that you're scrapping the previous one, even more so when you are allowed 'free' updates, as the regs stipulate this year.
"So as long as you don't use more than four elements for each designed PU component, you're basically free to do [swaps] at your leisure.
"What we did sits within this criteria of rotation."
Customer teams Sauber and Haas have also fitted new turbos to both their cars, with Marcus Ericsson, Pascal Wehrlein and Kevin Magnussen taking their second and Romain Grosjean his third.
Stoffel Vandoorne is the driver closest to receiving a grid penalty after the FIA confirmed he would take his fourth turbo and MGU-H of the season.
Honda has introduced a reliability update for this weekend's Russian Grand Prix following a series of MGU-H problems in Bahrain.