until Abu Dhabi Autonomous Racing League
Michelin has provided a major surprise leading into the final races of the 2019/20 Formula E title chase by adjusting the minimum tyre pressure for this weekend’s E-Prixs.
The Race can reveal that the change has been implemented with a view to spicing-up the action in the final crucial rounds and will mean the previous minimum tyre pressure is decreased from 1.4bar to 1.3bar.
The information was only communicated to teams yesterday afternoon, meaning they had a limited amount of time to amend set-ups and plan strategies for the final tranche of races beginning this evening.
The Race has learned that the pressure will be run for at least this weekend’s races and most likely for the final double-header event.
This will take place over next Wednesday and Thursday, and the new minimum pressure will remain should the weather conditions remain broadly the same as this weekend.
Michelin is understood to have been evaluating whether the significant change could be made safely for some time.
A Michelin spokesperson told The Race yesterday evening that “in Berlin the track is flat and there’s nothing that can damage the sides of the tyres.
“As the temperature is high and the track is very aggressive, it’s possible to move from 1.4 to 1.3.”
The move has received a split reaction from the paddock but most agree that it is likely to mix up the order on the traditional anti-clockwise configuration of track being used for the next pair of races, especially as temperatures are forecast to hit 30 degrees ambient at race start.
One senior engineer told The Race “if the surface is overheating then dropping the pressure helps because it increases the contact patch size and that reduces the temperature within it.
“It does however cause the casing to deflect more and can sometimes cause the internal temperatures to increase or standing waves in the construction to become a more regular feature.
“This tyre is bulletproof, though. Also the surface overheating has been a feature with the very aggressive concrete and aggregate surface.
“So I think it will be better and have less propensity for overheating at the surface and therefore less quick to go to oversteer.”
However, another leading engineer vented frustration at the timing of the decision, saying: “What is not nice is that it is announced so late!”
He added: “The implication for the set-up and lap time will be tricky. We can expect lap time to come down by about three tenths, I think.”
Despite a surprise washing of the track yesterday afternoon, the rubber on the circuit has only been partly cleared – meaning that grip levels are still expected to be high.
A temperature limited race is expected, with drivers having to look after their thermal temperatures during the E-Prix.
This, combined with the minimum pressure change, could mean lap times compared to the races earlier this week are “reduced by around 0.3s to 0.54s” per lap, according to one chief engineer.
While more grip is initially expected, the higher track temperatures could ensure that any advantages are shortlived.
“In the early races it was the left-rear [tyre] that got beat up, it was getting a kicking,” Audi team principal Allan McNish told The Race.
“This time, it’s going to be the right-rear because you’ve got that long entry to Turn 1, you’ve got the long entry at T5, and then you’ve got the long last corner as well.
“Therefore, it’s that right corner that you’re going to be trying to protect, and predominantly that comes from the driver and just the ability to sort of smooth out the corner as much as possible.”
