The Mercedes and Ferrari-powered teams have all introduced fresh engines in the opening practice at the Azerbaijan Grand Prix, but Formula 1 championship leader Red Bull will continue with its older Honda power unit.
Mercedes’ works team and its customers McLaren, Aston Martin, and Williams all used a new combustion engine, MGU-H, turbocharger, MGU-K, and exhaust system in FP1 on Friday.
Ferrari, Alfa Romeo, and Haas had new ICEs, turbos, and MGU-Hs while Ferrari drivers Charles Leclerc and Carlos Sainz are also running new MGU-Ks.
But the Renault and Honda-engined cars are still using the same power units that completed the first five grands prix of the season.
Alpine duo Fernando Alonso and Esteban Ocon have taken a new exhaust system though – Alonso’s fourth such change in five events, and the third for Ocon.
Opening practice pacesetter Max Verstappen had completed over 3000km across the opening five events of 2021, so his Honda will have significantly more mileage come qualifying and the race than Hamilton’s fresh Mercedes power unit.
The Baku circuit, which has the longest flat-out section on the calendar through the final sweeps and down the start-finish straight, is hugely demanding on the modern F1 engines.
It is a big test not only of outright performance but also of deployment of the energy recovery system.
Honda has closed the gap to Mercedes in terms of engine performance while Mercedes has battled an early-season deployment weakness at some tracks.
Sticking with the older unit is also a sign of Honda’s confidence in its reliability gains.
The Japanese manufacturer has not previously made it through a regular season without engine-related penalties but has felt since late-2019 it had reached a specification capable of doing so.
Honda’s major engine overhaul for 2021 did bring fresh reliability question marks, though, given the extent of the changes and the short period of time it had to complete the task.
Teams may use three of the combustion engine, turbo, MGU-H, and MGU-K each through the season without a penalty, and two each of the energy store, control electronics, and eight exhaust systems.
An ‘early’ change to the second set of components may seem like it stresses the rest of the allocation with so many races still to go.
Theoretically, there are 17 more weekends to complete after Baku, subject to the calendar being changed by the COVID-19 pandemic.
But the power unit components replaced by the likes of Mercedes and Ferrari this weekend will remain available all year.
So it is likely they saw a bigger benefit from introducing the fresh engines at a power-sensitive circuit and will manage their allocation through the year by using the higher-mileage parts during Friday practice and potentially at less power-sensitive circuits like Hungary.
