The Delhi-based Minda Auto Gas, which is the largest supplier of LPG kits to Maruti's Wagon R Duo and CNG kits to Hyundai Motors' Santro, says it has crossed the 30,000 kit-mark by the first half of the current fiscal year. The company said it had sold 40,867 LPG/CNG kits last year.

"The economic viability, the growing environmental concern and vast availability of LPG will propel the conversion kit market. In four years' time, 10 percent of the total vehicles in the personal segment will be LNG/CNG-fitted," said N.K. Minda, managing director of Minda Auto Gas.

"The after-sales retrofitting market is about 20 times larger than the OEM market for conversion kits. There are more than 20 players in the retrofitting business. Most of the fitments, about 70 percent, are done in small cars," said Arun Badia, chief executive officer of Auto Gas India.

"Every month we have 25 to 30 buyers who opt for retrofitting and the number is going up. The upward trend is here to stay since fuel conversion ensures at least 40 percent reductions in the fuel spending," said Kamal Chawla, sales manager of Sai Service, Mumbai.