Not sure what you're talking about. My father drives a Honda Civic GX (the only car factory built to run on CNG available to the general public). The car gets

Not sure what you're talking about. My father drives a Honda Civic GX (the only car factory built to run on CNG available to the general public). The car gets slightly more mileage on a tank of CNG than a similar car gets on a tank of petrol (although this is a difficult comparison to make due to the differences in fuel, storage, tank size, etc.). Point is, it goes just as far and it's much cheaper. I don't understand your argument that these vehicles are somehow less efficient than their counterparts.