Wow. I complain about paying $715 per year for two vehicles - my 06 Canyon and my wife's 10 Focus. Full coverage on both.
The vacuum gauge plus wheel covers helped increase summer 2015 mileage to 38.5 MPG, while summer 2016 mileage was 38.6 MPG without the wheel covers. Winter 2015-2016 was warmer than normal, so average mileage only dropped to 31.75 MPG.