Oklahoma Governor Mary Fallin is leading an initiative to put more natural-gas burning vehicles in 22 government fleets. As a result her state just ordered 256 natural-gas burning 2014 Ford F-150s, and the city of Dallas bought 65. They're hoping to realize reduced running cost and curtail greenhouse gas emissions.

Fallin's collation has determined use of CNG in their vehicles can lessens the environmental impact of greenhouse gas by 20%, and cut smog-producing pollutants up to 90%.

CNG ranges from $1.07 to $2.49 per gallon of gasoline equivalent in Oklahoma, while 87 octane petrol is about $3.43. The F-150 conversion, which is not done at a Ford factory but with Ford OEM parts by a Qualified Modifier, runs between $6,000 and $9,500 depending on tank capacity.

Oklahoma expects to recoup the upfront outlay in about three years.

Ford fleet sales manager Jon Coleman says Arkansas, Colorado, Louisiana, Mississippi and Texas have also expressed interest in a bulk order of Ford CNG vehicles. By summer 2014, the Blue Oval will have eight natural-gas upfits available, including variants of the Transit Connect and Transit van, E-Series variants, two F-Series Super Duty variants, The F-650, F-150, as well as the F53 and F59 stripped-chassis trucks.

Ford sells the only half-ton truck with factory CNG capability right now, which they make very clear with a million stickers on the thing, but and Ram have heavy duty CNG variants of their own and might have to elaborate their lineups if Governor Fallin's initiative pans out.

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Images: AP, Ford