Vijayawada, Sept. 10: The number of vehicles using compressed natural gas (CNG) is on the rise in the city with several advantages attracting the users of three-wheelers and four-wheelers. But supply of CNG is not in proportion to the demand. "The first advantage is the price. There is a difference of Rs 16 in the price between diesel and CNG. But the mileage is the same in both cases. This was the reason I have converted my autorickshaw to CNG," said Raju, an autodriver in Patamata. Diesel is available at Rs 38 per litre whereas the cost of one litre of CNG is Rs 22. The cost is not only the factor which attracts the vehicle owners to go for CNG. Lesser gas emission is also one of main aspects. Vijayawada has been recognised as a successful city in introducing CNG-run buses for first time in the state. "We established a record with 100 buses running on CNG without receiving any complaints so far," said Mr A. Koteswara Rao, regional manager of APSRTC. They have a dedicated plant of CNG at Vidyadharapuram depot and are planning to set up another plant at Governorpet. The number of vehicles using CNG is gradually increasing since 2005 in the city. As per the Regional Transport Authority, there are 1,200 autorickshaws running on CNG. With the increase in users of CNG, the supply is showing a negative trend as the number of filling stations is less in the city. As a result, the auto-rickshaws and cars have to wait for hours to get the gas filled in their vehicles. With only one plant catering to the needs of the city which is situated at Kotturu Tadepalli, scarcity is being encountered by the users. "We feel uncomfortable to go to the outskirts of the city where these CNG filling stations are located," complained a car owner in Gandhinagar. CNG filling stations are spread over in the suburbs.