$7,000 more for the GX over the equivalent gasoline LX.
-50% or $3,500 from Oklahoma state income tax CREDIT, not deduction.
$3,500 out of your pocket.
Now for the fuel savings,
$3.50 gasoline vs $1.40 CNG - $2.10 savings per gallon.
35 mpg for both LX and GX.
$3,500 / $2.10 = 1,666 gallons x 35 mpg = 59,000 miles.
I'm glad I bought my Civic when the federal government was handing out $4,000 fed income tax credits. I have been saving money since I drove it off the Joe Marina lot in late 2009. You want the fed credit back? Write your congressman to support the NAT GAS act.