I thoroughly enjoy this car.
The fuel economy is far better than i expected. I have gotten as high as 40 mpg , and with each gallon of natural gas costing $2.05 , this has translated into an mpg equivalent of gasoline of 80 mpg ((when gas is at $4.00 for unleaded gas).
I am waiting for the diamond lane sticker which will save me at least 10 minutes each way to and from work.
One thing to note is in California there are many natural gas stations. The lowest price stations are the actual gas companies at 2.05 per gallon.
Others will charge as high as $2.99 which is 33% more
2012 Civic NG bought new for 21k fall 2013 (dealer left over), sold for 6k end of 2015 with 229,000 miles. Used as a courier delivery vehicle on 3-700 mile per day routes. Hwy mileage through hilly western PA driving 60-80mph averaged 45mpg annually (mind you this is long range hwy driving). Mixed 50/50 city hwy around 35, city low 20's. Best was hypermiling round trip through flat Ohio in summer, 58mph, no AC; dash read 61mpge but actual trip miles divided by gge at station (same pump similar psi) was over 63mpge. That's 63 miles on $1.90 worth of fuel!
Total maintenance and repair history for the nearly quarter million miles entails;
Full synth oil/filter changes every 25k miles. (oil analysis three times by Black Stone Labs indicated oil was nearing end of life at 25k).
I try to change both fuel filters at 40k. Rear easy, front used breaker bar and housing bent rather than loosened. Cost to replace the housing part only was
over $600!!! It was essentially a glorified canister not very robust either. F U Honda! Manual says change rear every 30k and front every 15k is factually
inaccurate. I did a drain on rear every 15, change rear at 30 and front every 60k and both filters were nearing end of life. Dealer charges $80 labor for front
and my local guy charges $15 because it takes 10 minutes.
Drivers side wheel bearing started to go bad at 60k miles likely because of tires kept at 44psi. Wheel bearing changed at 103k, tires deflated to 34psi and no
Timing and plugs at dealer at 125k miles. Vehicle began idling poorly and mpg drops 10%. Took to local mechanic and had timing again and solved problem.
Transmission changed every 100k miles, coolant never changed.
Both low beams and one high beam replaced at some point towards the end.
Sold car at 229,xxx miles with no other issues. If I had taken to local mechanic for front fuel filter change and kept tires at normal levels, I'm guessing there wouldn't have been any issues. The interior is a little cheap but is comfy and controls are intuitive. Seat comfort is middling although not nearly as bad as the 2016 I bought afterward which I had to sell after ten months because I was in such pain driving it. The engine really struggles up hills and jerky down shifts to maintain speed but the flip side is impressive fuel economy even for a Civic. Overall this is a great car if you have adequate filling stations around you. The 8gge tank realistically holds 7-7.5gge and as little as 6.5 gallons if temps are sub freezing or your station happens to not work correctly which happens relatively often. I have been stranded more than once because cold weather or lack of maintenance at stations.
Hope this helps!
I've been driving this natural gas car for over a year now and it has turned out to be one of the best investments ever. I have two CNG stations by my home and my tank fills up with $12 and I get anywhere from 200-240 miles per tank. The only bad thing I have notice and have taken my car back to dealer for was the sputtering when you first start the car in the morning. It did hesitate in the morning sometimes, but the dealer did some adjustments and it's all good now. Overall a great comfortable car with great steering/handling. The navigation and stereo is GREAT!! The carpool stickers in rush hour is the BEST part!!! Love this car.
The car is quiet, comfortable, lots of leg and rear seat leg room. Trunk is shallow but tall and will fit two small suit cases. Very areodynamic and does well in strong cross winds, is light weight (2848lbs. for the CNG) yet steering is a little heavy but not that bad! Few minor quirks; the radio volume isn't loud enough to hear clearly (on max) when playing classical music, miles 'til zero range indicator fluctuates and settles esp the first half tank, trunk squeaks, car sputters when you first start it and hesitates when initially pressing the gas. As well it frequently acts like it's in neutral when you come to a stop so will roll backwards slightly on a hill. No coolant temp guage!
Update. I sold this car at 230k miles (used as a courier delivery vehicle) and I only had to do basic maintenance fluids filters, tires, I did have it timed at 125k. Original brake pads with 30% life left... 230,000 miles! I bought a 2016 Civic and it's not nearly as soft a ride. Firm suspension while a thrill to drive (and the car is much better generally than the previous generation), it's killing my back and I'll be selling for something softer.
The 2012 isn't a looker, it isn't interesting or special to drive. It's just an honest, efficient well built car that needs next to nothing for hundreds of thousands of miles. I'm sad that Honda stopped making the Natural Gas version of the Civic after 2015. With a larger tank in the larger trunk for the 2016 model, I would have likely bought the cng version.