Well this witner I’m gonna be putting in 5w30 Castrol GTX (regular), but
come spring/summer, I wanna switch to synthetic.
I’m thinking of switching to Amsoil synethetic. It’s expensive, but will
it be really worth it? I mean, will a KA really benefit from such an oil?
Other options are Mobil 1 or Royal Purple.
I’ll need the KA for next year, but like everyone else, I wanna get an SR eventually. 
5w50 castrol syntec right now (thanks sasha)… i had mobil 10w30 but i want a 5w for the winter in the SR
syntec…was 10w30 but don’t know now
5w50 castrol
np dude
castrol syntec
or mobil 1
Castrol Syntec 5w30
Id only run sythetic in my KA if i got it for free or if it cost the same as Conventional Oil.
Theres no point in running it unless your on the track at least once a week, or used it since day one.
I just use 5w30 in the winter and 5w50 in the summer.
Take a gander at this guys you might find it interesting.