i only worked on petrol car, if any of mine came to me and ask for such thing, i simply suggest him for kit and cylinder service, how ever on a petrol tuned car, your inhale must be clean, 02 should not be clogged, your fuel filter ( intank) and in the bay should be replaced at 30k according to pak condition. they surly give healthy air and fuel to engine, so it should perform better, it work for me too, at first it was giving 6-7km/l after such work, 10-12km/l i got