X 2002 Honda Civic CNG

1.7 L, 4 cyl, Auto (variable gear ratios), Natural Gas

EPA Fuel Economy

Combined: 28 MPG

City: 26 MPG

Highway: 31 MPG

X 2001 GMC Sierra 1500 2WD

5.3 L, 8 cyl, Auto 4-spd, Regular Gasoline

EPA Fuel Economy

Combined: 15 MPG

City: 14 MPG

Highway: 18 MPG