Recommended fluid

[SteveRB240sx]

Well Im going to be beating on my stock Z31 N/A with a VG30E at the track in a few weeks and i was wondering what weight oil i should use since im going to be running it hard.

Normal calls for 10w30 or 10w40, should i run something like a straight 40?And my buddy thinks i should run Castrol GTX in it, since its older.

[SteveRB240sx]

so no one runs their z31 with the old stock engine hard?

[evildky]

I run mobil 1 5w30

[SteveRB240sx]

thanks man, i will look into that, i would like to try to keep my VG running for as long as i can.