DETROIT, MI- Even with more automakers offering compressed natural gas vehicles to retail customers, officials expect the majority of sales to remain in the fleet market for years to come.

According to analysts, the vehicles being offered by automakers to U.S. retail customers only make sense to a small group of people who are not fleet or commercial customers.

"I don't want to seem too negative about the consumer vehicles, but the consumer vehicles have to follow the fleet vehicles," said Richard Kolodziej, president of National Gas Vehicles for America.

Kolodziej’s trade organization, which represents more than 150 companies, environmental groups, and government organizations, estimates there are about 120,000 natural gas vehicles on U.S. roads today and more than 15.2 million worldwide.

Of the nearly dozen dedicated and bi-fuel CNG vehicles being produced in North America to retail and fleet customers from mainstream automakers, only Honda's Civic Natural Gas is not a heavy-duty pickup, van or chassis.

Dedicated natural gas vehicles are designed to run on natural gas only, while dual-fuel or bi-fuel vehicles can also run on gasoline or diesel.

CNG vehicles, according to analyst, face numerous of the same challenges as electrified vehicles. There is a lack of infrastructure, low demand, higher pricing and range anxiety issues if not a bi-fuel vehicle.

"CNG is tough because without being a fleet, you don't have a guaranteed location to fill it up," said Karl Brauer, editor in chief and CEO of Total Car Score. "So, you can get into a range anxiety issue with CNG, especially since they offer lower tank capacities and lower fuel mileage, thus lower range than a traditional gasoline version of the same car."

Besides fuel issues, Brauer said the demand for CNG vehicles just isn’t there yet because the vehicles “costs more, have lower fuel range, and worse fuel mileage, with reduced cargo space.”

As of May 1, Honda had sold more than 14,000 of the Civic Natural Gas models, according to Angie Nucci, Honda senior environment and safety PR specialist. The vehicles went on sale in 1998, which averages out to about 1,000 per year.

Nucci said the vehicle is on pace for record sales this year, partially thanks to Honda expanding its certified-dealer network to nearly 200 in 36 states.

“We’re coming off of a record year last year, and we look like we’re heading in that same direction this year,” she said.

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Honda does not release monthly sales figures for the vehicle, but Edmunds.com reports the Japanese automaker, which produces the vehicles in Indiana, sold 1,065 of the vehicles through August of this year, a 12 percent increase from the same time period a year ago.

The Civic Natural Gas costs about $5,000 more than its sister gasoline model the Civic EX, which starts at $20,505. The price is much lower than the $11,000 or so increase for the bi-fuel options on the pickup trucks and heavy-duty vehicles now being offered by the Detroit Three.

Jessica Caldwell, Edmunds.com senior analyst and director of pricing and industry analysis, said retail customers that purchase CNG vehicles are primarily early adopters because unless the infrastructure is near you, the vehicles aren't a great option.

“This is definitely a niche type of customer,” she said. “This is going to be somebody who is really looking at the payoff and saying, 'I have something different.'

“Really, this is not a mainstream solution for a lot of people.”

Excluding private CNG stations, there are about 550 stations in the U.S. for drivers to fill-up on the mostly methane gas, according to the

Thirteen of those are in Michigan

.

However, there is hope for the CNG retail market place thanks to fleet customers.

The CNG fueling stations are growing at a monthly rate of 20-25 per month as more vehicles – particularly fleet – enter the market, according to Kolodziej.

CNG fleet and commercial vehicles, unlike electrified, are growing at a substantial rate. About 50-55 percent of new garbage trucks this year are expected to be powered by CNG and other companies, including AT&T and DTE Energy have started turning their vehicles into CNG.

Once the fleet and more stations, the retail should follow thanks the numerous advantages CNG vehicles have to offer.

“I don’t know of any study that says we’re not going to grow significantly over the next 5, 10, 15, 20, 40 years,” Kolodziej said.

Editor's note: This is the second article in a three-part series regarding the U.S. automotive industry and bi-fuel, CNG vehicles. Follow the series here or check back to MLive.com each morning.