Hi, I was doing a similar survey for my friend sometime back,who was planning to buy a new Esteem with CNG operation, though I too have a honda and swift for my personal use but without CNG. I understand BRC ( Make imported Italy) with lamda system is the best option now. It is Euro 3 approved.Though most of call Taxis are fitted with BRC with closed loop system. The cost for BRC lamda system is Rs 38,000 inclusive of everything while closed loop system costs Rs 51,000. Only the wiring part is indigenous ( made by Rohan automotive of Ahmedabad0, rest it is totally imported except cyliner having 12 kg carring capacity.) I have heard that one company in okhla who are the dealers of BRC lamda system and install it at Rs 38,000 plus approx 1500 extra for for RC updation. I just have the name Mr. Schdeva Cell no 9312252055 and address in somehwre in okhla. For closed loop system, you can contact Service masters , contact name Manoj at cell no 9310574812. Hope info may be of little help to you. It would be great if you can inform me when you finnaly instal one in your honda about the performance, so that it gives me an operational idea if I plan for my honda. Thanks and Regards