I am a n00bish when it comes to actual matters of motor oil. I have a 10 Mazdaspeed3(2.3L Trbo.) I'm just over 700miles on the motor and i will be doing the initial oil change at 1K miles. This car is my daily driver and AutoX work horse. On my daily commute i do drive the car somewhat hard around corners, and WOT pulls after its been warmed up. I wanted to start using Redline oil in it but i'm not sure if i should user 0w30 or 0w40. From my brief time on her i know that heavier isn't always better. I just wasn't sure of going with the heavier weight because of driving habits.