i have an auto 2.3 too but my nearest track is a 1/8 so all i can say is i ran 10.4 on the 1/8
06 Ultra Silver Cobalt LS 5 Speed
PERFORMANCE: -Custom 2.5 SS/Magnaflow Catback -Pacesetter Race Header -GM CAI
EXTERIOR: -Razzi body kit
*NEEDS TO GO: FS DURATEC STRUT BAR 50$ -ZX3/ZX5 SIDE SKIRTS PM ME!!