OKLAHOMA CITY (AP) - Oklahoma State Auditor and Inspector Gary Jones has added eight compressed natural gas cars to replace some of the office's older vehicles.

Jones' office said Thursday that the eight new Honda Civics will save an estimated $20,000 in vehicle maintenance and fuel costs over the life of the cars. The auditor's office says it will add another nine compressed natural gas vehicles in the next two weeks and plans to convert more. The cars average 31 miles per gallon.

The agency's auditors drive tens of thousands of miles each year conducting audits of county government and investigative audits of suspected fraud and waste.

Gov. Mary Fallin has urged other states to use vehicles fueled by domestically produced compressed natural gas to move the nation toward energy independence.