My turbo K4 specifically says to use nothing but 87. I thought, how odd. Nope, they tuned the Smartstream 1.6T to run very conservatively stock to use 87, any other fuel is wasted.

It doesn't have another map for a higher octane, unlike Mazda which has some sort of black magic to push timing until it micro-knocks and then pulls back timing. Kinda cool.

Shame on Hyundai / Kia. JB4 time soon!