The older cultus is a bad bad car. This doesn't makes WagonR a better car.
But the old cultus is literally a Margalla which means it's a 90s car. Getting in and out of it is trouble some. Bad seats, old feels everywhere.
On the other hand Wagonr is a modern car, modern engine. But it looks like a box.
Old cultus manages 11-13 kmpl in city driving.
WagonR manages 11-12 (with me being 50k driven).