Hamilton, who is under investigation for a DRS infringement in qualifying, has taken a new internal combustion engine for this weekend’s Brazilian Grand Prix and will serve a five-place grid penalty on Sunday.
The Mercedes situation is a surprise considering how little trouble it has faced with reliability throughout the turbo hybrid era, with Honda’s F1 technical chief Toyoharu Tanabe remarking that he “cannot believe” why its rival has struggled so much.
However, team boss Toto Wolff thinks the current difficulties are a consequence of Mercedes having over-reached in chasing performance during the 2019 campaign – when Ferrari had a power advantage.
That season proved controversial with Ferrari’s power unit being subject to an FIA investigation about potential behaviour that got around F1’s strict fuel flow limits.
While the FIA was unable to prove that Ferrari broke the regulations, the subsequent introduction of an extra fuel flow sensor served to pull the Italian team’s performance back.
At the time, Mercedes was upset because it felt that its staff had been pushed to their limits to match the Ferrari performance that it felt had been the result of the Italian team pushing the boundaries of the rules.
Now, Wolff suggests that measures it took back then to play catch up for 2020 are now coming back to haunt it.
“We were pushed very hard in 2019, and came with a power unit in 2020 that was right there, but maybe it stretched us too much,” explained Wolff.
“If you are in the constant pursuit of performance, sometimes reliability falls behind. And I guess this is what happened.”
Lewis Hamilton, Mercedes W12
Photo by: Steve Etherington / Motorsport Images
While Mercedes has understood a lot more about its reliability problems in recent weeks, the decision to change Hamilton’s engine for Brazil came because of concerns over performance degradation.
With the team needing to wind down power at the end of each engine’s life, it felt that giving Hamilton a boost with a fresh power unit made most sense.
Wolff added: “We are not yet 100 percent comfortable from our side from reliability and from the degradation side. What we know for sure is that we are losing power the more we run that.
“That’s why we wouldn’t want to continue to run this current power unit and end up in Saudi or Abu Dhabi with not much more left, if we’re still in the championship.”
Despite not being fully on top of its engine reliability right now, Wolff says that Mercedes cannot ease off with its performance push ahead of a looming development freeze.
“You need to push hard,” he said.
“We are fighting an extremely potent and reliable Honda engine, and these guys have put all the resource that you can potentially deploy on this last season. Fair enough.
“And that will continue to be the power unit in the next few years, in some way in a frozen manner.
“Therefore we just need to make sure next year we start with an engine that is as good in performance as we have now, but that can actually go through the seasons without incurring engine penalties.”