GREENSBURG, Ind. — Indiana’s newest auto plant will make one of the cleanest and greenest Honda Civics in the world.Civic GX is a $25,000 commuter car that runs only on natural gas — going about 192 miles in city driving on an 8-gallon fuel tank that currently costs about $16 to refill at Indianapolis natural gas stations.Honda will produce 2,000 GX models next year when it shifts production to the new Greensburg plant from another Honda plant in East Liberty, Ohio, which is winding down all Civic production, Honda President Takeo Fukio confirmed Monday.The GX will account for 1 percent of the 200,000 vehicles the plant will produce every year, but making the GX in Greensburg will hand Indiana a new distinction as the source of green auto parts and cars.Many of the automotive plants in the state can make the vital insides of hybrid electrical systems. Now the state also can claim it will make the only auto for everyday drivers on dealer car lots that runs cleaner than a hybrid and uses the most abundant energy source in America after coal: natural gas.Hybrid and diesel cars have gotten all the headlines as gasoline prices soared. Except for a few business fleets and some bus lines, natural gas has been low on the shopping list for most motorists, largely because refueling stations are scarce.The Web site www.cngprices .com shows three refueling stations in metropolitan Indianapolis, compared with about three dozen in the Los Angeles area.Honda, though, quietly has lured regular drivers to its GX model, selling about 2,000 natural gas Civics each year, chiefly in California and New York.Honda began to supply fleets with natural gas Civics in 1998. By 2005, it had put the GX model on car lots for ordinary drivers. About 1,000 GX models were sold in 2005. The volume has doubled in the past two years, said Todd Mittleman, a Honda environmental specialist.“We can only build so many of these cars. The (refueling) infrastructure only can support so many,” Mittleman said. “We focused our marketing efforts on New York and California. These two states have the most extensive infrastructure.”Drivers also can have a $4,000 refueling kit hooked up in their garage. It draws fuel from the home’s natural gas pipeline. Installation costs another $1,500. A federal rebate can shave $1,000 off the kit price, Mittleman said.The GX is priced at $25,090. This includes sturdier pistons and a tough fuel tank made with bulletproof Kevlar. It’s located in the trunk. A $4,000 federal tax credit is available. California offers its residents an additional $3,000 rebate, Mittleman said.Mileage on the GX equates to 24 miles per gallon in the city and 36 mpg on the freeway.New gasoline Civics are priced at $17,355 for the LX base model, which is rated 26 mpg in the city, 34 mpg on the open road.Civic Hybrids are priced at $23,550 and rated 40 mpg in the city and 45 mpg on the freeway.Where the natural gas vehicle makes a difference is emissions. The hybrid still sends gasoline exhaust through the tailpipe.“If you spill a pint of gasoline, you’ll release more unburned hydrocarbons than the GX will emit in 100,000 miles,” Mittleman said.