Lewis Hamilton seems to have no luck with his W13 this season. During the Mexican Grand Prix the 7-times World Champion complained of his engine cutting out both in qualifying and race.
In the course of the race debrief the Mercedes Motorsport Strategy Director James Vowles explained that the origin of this issue is connected to the altitude of the track. The Autodromo Hermanos Rodríguez is in fact at 2285m above sea level and the Power Unit at that altitude is not quite producing the same power as it would at sea level.
“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,” explained Vowles in the team's post-race video - “when you suddenly go to these levels of altitude you are in a very different condition and 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.”
In the course of qualifying this factor has more obvious consequences than the race, given the speeds that are reached and the greater power that is applied to the throttle pedal.
Hamilton did actually a good qualifying session, setting the third best time, but the engine problem did cost him a bit of performance. During the race the problem was therefore more marginal, but it still affected his run.
“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,” said Vowles.
“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.”