11/28/2022 Sonoma Raceway HPDE, GR86 with OEM Michelin PS4 tires,

I am a bit curious about OEM Michelin Pilot Sports 4 tires' performance at track so I test them at Sonoma. The peak grip is actually pretty good and I did 1:56.8 lap right after the outlap in the first session, slightly faster than what I did 4 months ago using the wider GT Radial SX2 tires, which are the spec tires used in 86Cup/86DriveChallenge. However, these Michelins overheats easily and has very obvious grip drops when they heats up. It is quite difficult to drive a consistent pace without cool down laps. I slightly improved my laptime in the 2nd session even with a bit of traffic and mistakes as shown in this video. Judging from logged data, it should be possible to put down a 1:55.6 lap if there is no traffic and no mistakes.

Mods:
86DC stock class build
OEM 215/40/18 Michelin Pilot Sports 4 on OEM 18x7.5 wheels
G-Loc R10/R12 pads, AP Racing Endurance BBK.
Jackson Racing GR86 oil cooler with customized Goodridge 910 hoses
DOT4 fluid
PED-580096 offset tophat with camber bolt
Camber: Front -2.3. Rear, -1.7 L, -0.9R,(Not adjustable). Toe: Front:0, Rear: 1/32 in