maintenance 2001 Impreza WRX STI oil change

[ajh20_06]

I have just purchased a 2001 Impreza WRX STI and want to do an oil change before I drive it a major distance. It is a Japanese import and has unequal headers, what oil / filter would be best as I have seen posts claiming 5W-40, but Subaru states 5W-30? I am in the Midlands so there are rarely any extreme temperatures. Any advice would be greatly welcomed!

[SOC Admin]

I use Castrol's Oil Selector site to determine specifications for the correct oil (whether you use castrol or another brand), make sure you go by the ACI specs (ACEA C3 / API SN/CF, etc)  rather than the weight of the oil (e.g. 5w30)

https://www.castrol.com/en_gb/united-kingdom/home/product-finder.html?page=recommendedProducts&id=89704