I read a lot about this car prior to purchase and concluded it was a great idea. It was hard to find one--called around a lot and the few places that had them in the country wanted top dollar. Eventually found one out of state and purchased end of month--got a reasonable deal. It is an awesome commuter car--very cheap to run, extremely reliable, clean burning, carpool lane exemption, and dare I say, even fun to drive. No, certainly not a sports car, but it corners well, stops well, and accelerates decently. CNG is well below the price of regular unleaded-- about 40-50% for me, and I'm not Utah--I'm surprised everyone there doesn't have one! My kids, boss and others say "cool!"
I bought the Civic GX because I love the idea of using natural gas instead of petroleum. The engine is smooth, although somewhat underpowered. The car handles surprisingly well, despite having a big (and obviously heavy) tank behind the back seat. I average around 37 mpg, in mostly freeway driving. Mileage drops considerably on short city trips. Dashboard layout and visibility are excellent. The driver's seat unfortunately is undersized, poorly designed and uncomfortable (the seat in the Corolla is substantially better). E-brake in the knee underscores that the Civic is designed for small drivers.
I have been driving the car for 3 days now. I commute 150 miles each day. The first day it ate fuel, the 2nd day not so bad, and by day 3 it is improving more. The best part: I do not get robbed at the pump! I have the FuelMaker FMQ2-36 instead of the Phill unit. I waited 3 months to get that and it is nice to just back into the driveway and plug the car in for the night. FuelMaker needs to step up availability. My fuel bill for gasoline would be over $13,000 per year and this cuts it down to a more tolerable $3500 per year. Much easier on the pocket book. I am going to install another 2 gallon tank in the trunk to up the capacity to 10 total this spring.