Autosport web reports inside of GT500 Lexus squad.
http://www.as-web.jp/supergt/351314?all
*It seems that the Lexus squad (BS user) is split in light and dark.
Good: LeMans (#6)
So-so: Tom's (#36, #37), Cerumo (#38)
Bad: SARD (#39)
*One of the factors is the new BS tire which has new structure.
Rear grip is better than that of front, so it becomes understeering.
*Another factor is deterioration of the front splitter.
It interferes with the road surface and it is shaved and becomes understeering.
If the front splitter is replaced with a new one, its symptoms will be improved.