1. Weight Matters Extra weight on your car will make your car engine work harder and therefore reduces the mileage. It seems easier to leave the beach chairs, kids' sports gear or cases of water in the trunk, avoid keeping heavy or unnecessary objects in the car and when they're not in use find somewhere else to keep these items. Extra 100 pounds in the car can reduce a typical car's fuel mileage by 2%. Reducing the load has a green impact too: 20 pounds of CO2 is prevented from entering the environment, for each gallon of extra gasoline saved. 2. Proper Tire Pressure. Correct tire pressure improves mileage by 3%. At today's gas prices, 10 cents per gallon can be saved by getting more mileage from each gallon. Buy an inexpensive tire gauge and you can check your tire pressure monthly or during car service , when transporting heavy items and before long trips. Correct tire pressure for cars can be found in the owner's manual or in drive...