Summerize your car

Replace/Tighten Your Gas Cap – Fuel evaporates through gas caps with broken or weak seals, potentially reducing your efficiency by 2 percent, polluting the air and allowing contaminants and dirt into your fuel. Make sure you keep that seal by thoroughly tightening the cap every time you fill up. And if the seal is bad, you will probably need to replace the entire cap. Usually a check engine light will come on if the seal is broken.