James Vowles has explained it was the high altitude of the Autodromo Hermanos Rodriguez that caused engine issues for both Mercedes drivers in Mexico.
Lewis Hamilton complained of his engine cutting out in qualifying for the Mexican Grand Prix with the Briton finishing third fastest, five thousandths of a second off his team-mate George Russell’s time.
Hamilton explained that the issue “started to appear in Q2” and then began to occur on “every run in Q3, basically dropping out of power on exits from corners.”
It was more of the same in Sunday’s grand prix, Hamilton’s PU sporadically cutting out, while Russell was also affected with delays in power delivery.
Vowles explained that Mercedes’ engine is not mapped out for the altitude of the Autodromo Hermanos Rodriguez which sits 2,285 metres above sea level.
That means the drivers suffer the occasional loss of power, or a feeling that the engine is not delivering as it should.
He reckons it was a problem Mercedes’ rivals also faced.
“We were suffering a little bit with engine cuts and here is the reason why,” Vowles, Mercedes’ motorsport strategy director, said in the team’s debrief.
“You generally map the engine for the conditions it is most used in which is sea level, that’s where most of the racing takes place, when you suddenly go to these levels of altitude you are in a very different condition.
“Instead of having an engine that is really highly tuned you are back into a condition where you have to do lots of work with the Power Unit in a very short space of time to try and map out these irregularities.
“I am confident all teams will suffer this it won’t be unique to ourselves.
“It’s typically accentuated in qualifying because you are very quickly and rapidly applying throttle pedal which means that the turbo and fuelling systems need to keep up with that change very quickly and normally it’s better in the race.
“We were hoping that the race would not be as bad and it comes from a factor when the drivers are requesting throttle and picking up throttle it was simply not delivering the power they request quick enough, so enough fuel or enough air.
“It can be tuned out in time and were we got to in the race wasn’t a bad position, I think qualifying was worse, but still enough to cause a small amount of performance loss for both drivers.”
Despite his engine cutting out on him, Hamilton raced to second place with Russell P4 on the day.
Mercedes closed the gap to Ferrari to just 40 points in the Constructors’ Championship.