F1 championship leader Max Verstappen and runner-up Charles Leclerc will be chasing from behind in Sunday's Belgian Grand Prix as the result of their respective tactical power unit changes.
In the Red Bull camp, the team has opted to add a fresh engine, turbocharger, MGU-H, MGU-K, energy store and control electronics to Verstappen PU inventory.
At Ferrari, the Italian outfit has added a fifth power unit and a new gearbox to Leclerc's hardware inventory.
The changes should make for a spirited fight between Verstappen and Leclerc at the start of the race as they carve their way through the field, although it is believed that Ferrari may have exploited a timing loophole in the sporting regulations that could see Leclerc's overall grid penalty limited to 15 places.
In any case, the two protagonists could find themselves in good company in the second half of the field as McLaren's Lando Norris, Alpine's Esteban Ocon and Alfa Romeo's Valtteri Bottas are also set for component changes and grid penalties.
Norris and Ocon have both received new ICEs, turbochargers, control electronics and MGU-Hs, while the Frenchman has also been handed a new MGU-K and energy store.
Alfa has added a fresh engine, MGU-H, turbocharger and a new gearbox to Bottas' hardware.
Finally, over at Haas, Mick Schumacher is in line for a penalty following a control electronics and gearbox change.
The FIA is set to officially confirm the raft of PU changes at the end of Friday's running.
Keep up to date with all the F1 news via Facebook and Twitter
