I own a 1997 Opel Astra. I love the car the petrol prices is killing me. The car returns approx 10kmpl in the city and approx. 13kmpl on the highway. There are no mechanical problems with the car and it's a dream to drive. But i'm looking to fit the car with a CNG kit but unsure if it's good of the car. The mechanics have discouraged against getting the car fitted with the kit since it "misses" and there are "knocking" problems. I would like to ask if fitting with the car with the kit a good option, how much would it cost or if there are any other options that I may have? I really don't feel like selling off the car.