This article (Masakiyo Kojima interview) explains revised point of 2018 TS050 powertrain.
https://jp.motorsport.com/wec/news/w...gazoo-1037671/
*Engine:
Reliability is improved. And fine-tuning was done.
*Battery:
Since the heat resistance of the battery improved,
the cooling system parts became lighter and simplified.
*Fuel:
Since fuel changed to TOTAL, they had difficulty in optimization.
Although the problem is solved at present, unexpected parts broke in the beginning.