Is CNG worth more than just a sticker that gets you carpool lane access in California? We find out.

California and Oklahoma have one thing in common: An interest in promoting compressed natural gas as a fuel for motor vehicles.

Frankly, we'd be surprised if the Eureka! State and the Sooner State can agree on anything else, but at least their senators have one shared goal to discuss over taxpayer-funded luncheons in Washington.

The CNG infrastructure is expanding at a faster pace across the country than you might expect. Not wanting to be caught in the slow lane - literally, at least in California - we decided to hop behind the wheel of the only CNG-fueled standard passenger car available in all 50 states, a 2012 Honda Civic Natural Gas.

Yes, other CNG cars exist, but they're mostly pickups and buses aimed at fleet buyers. Our test car arrived about a year ago to replace the oddly-named, market-restricted Civic GX. The more simple nomenclature reveals Honda's plan with the Civic Natural Gas: To make it appeal to just about anyone.

And in California, that's quickly becoming anyone who wants to get somewhere quickly - but not because the Civic Natural Gas is anything approaching fast. No, the Civic Natural Gas currently qualifies for access to speedier carpool lanes in the state's congested cities regardless of the number of occupants aboard, something only a handful of other vehicles - including EVs and some plug-in hybrids - can boast.

It would be cynical of us to assume that all Civic Natural Gas buyers in California signed on the dotted line just to get the some stickers for their bumpers. No doubt many buyers are intrigued by CNG, which, unlike gasoline, is actually a gas when it sits in the high-pressure cylindrical fuel tank that takes up the bulk of the Civic's trunk. Pack lightly - our Civic was filled to the max with two carry-on suitcases.

CNG combustion is cleaner than that of gasoline or diesel, and it's actually much less flammable in the event of a wreck that punctures its tank in part because it disperses extremely quickly. The fuel is also quite a bit less costly per gallon equivalent, which means it's actually cheaper to run a CNG vehicle than a gasoline-powered one.

On the downside, there's no shortage of controversy over the way domestic natural gas is extracted from the earth in places like Wyoming, Texas and Pennsylvania - pick your poison between fracking, water quality and air quality, although environmentalists do generally agree that natural gas drilling produces fewer greenhouse emissions than crude oil.

Carpool lane cruising

On the road, our Civic tester's 110 horsepower 1.8-liter four-cylinder was certainly no powerhouse compared to the 140-pony standard Civic. The five-speed automatic did its best to keep what power was on hand accessible, but freeway merging to take advantage of those carpool lanes is a full-throttle affair.

Inside the carpool lanes, we saw several earlier Civic CNGs enjoying the same privilege. One owner even gave us a nod of recognition, which is something of a rarity in an area that has long since given up on the courtesy wave.

Aside from its pokiness, the Civic Natural Gas plods along about like any other 2012 Civic - a nice way of saying that we're really looking forward to the 2013 updates.

Still, a general sense of normalcy pervades, at least until you visit the refilling station. The Civic's optional navigation system directed us to refuel at a station across from LAX, where we parked among buses, vans and stinky garbage trucks - the kind of vehicles you don't see at your neighborhood Shell. First time visitors are instructed to watch a roughly 90 second video teaches how to refill CNG cars. The video displays a two-digit code that's tied to your form of payment so you can bypass the instructions on your next visit.

We learned how to plug the pump's nozzle into the Civic's CNG port, which looks like a miniaturized version of a standard Civic's. Once the nozzle is in place, a quick twist of a handle locks it in. Pumping begins with a series of whooshes and whirs worthy of a Jetsons clip, but it only took about a minute to top off our half full Civic tank at a cost about 2/3s of what we would have paid to fill a gasoline model.

Our Civic achieved about 43 mpg on a jaunt from John Wayne Airport in Orange County to LAX, about what we'd expect to see in a standard Civic. We also achieved more than 33 mpg in mixed driving, which included some snarled traffic even in the carpool lane. Either way, our findings bested the EPA-rated 27/38 mpg (31 mpg combined) Honda puts on the car's window sticker.

Leftlane's bottom line

Is a CNG car right for you? If you're a Southern California commuter or you live where CNG stations are close enough to be convenient, there's something to be said about skipping traffic and trying something new. If you live elsewhere, the benefits are more centered around the undeniable environmental benefits of natural gas.

Still, we can't help but think that a more powerful CNG-fueled engine would make more practical sense in a larger vehicle - like Honda's own CR-V - simply because of the major trunk space compromise. Until a CNG engine can be made efficient enough to use a smaller fuel tank - something happening in most gasoline-powered cars - they'll probably remain a novelty. But that's something we wouldn't have said a few years ago, when the CNG infrastructure was in its infancy.

Progress? It sure seems like it.

Words and photos by Andrew Ganz.

Current CNG stations: