Keep Your Engine Properly Tuned for Batter lifespan

Fixing a car that is noticeably out of tune or has failed an emissions test can improve its gas mileage by an average of 4 percent, though results vary based on the kind of repair and how well it is done.

Fixing a serious maintenance problem, such as a faulty oxygen sensor, can improve your mileage by as much as 40 percent.

Fuel Economy Benefit: 4%
Equivalent Gasoline Savings: $0.08/gallon