4th Generation Optima (2016 - 2020)
3"? 3.5"? Because some of the pre-made kits (i.e. AEM) have a useless heat shield and the intake temp for a GDI engine isn't as critical, I may order the Airraid DIY CAI kit but need to know the tubing diameter.
I am hoping this may provide opportunity for a closer to cold air intake depending...