You don’t need a quite motorway or high rpm, rather allow the car to slow down naturally or use of the gears, to allow engine breaking is all thats needed. Using a mix of E5/E10 also helps if you do short journeys.
Because of the forever tighter emmissions controls GDI engines have become increasingly popular with manufacturers over port injection, which brings its own sets of issues. Both Hyundai/Kia use GDI engines.