Auto expert and off road race car driver Barbara Terry gave us useful car maintenance tips if you're hitting the road this 4th of July weekend. For more information on Barbara Terry visit www.barbaraterry.com

Pressure Check: Check your tire pressure at least once a month. Many drivers can improve their gas mileage by more than 3 percent simply by keeping their tires properly inflated. The correct tire inflation pressure is critical for good fuel economy, maximum tire life and proper vehicle handling performance. The recommended pressure number for your vehicle is located on a sticker inside the driver side door or in the owner's manual, not the maximum inflation pressure stamped on the tire.

Filter That Air: Check that your air filter isn't clogged. Replacing a clogged air filter can improve a car's gas mileage by as much as 10 percent. And it won't just save you money; it will also help protect your engine by keeping harmful impurities out.

Keep The Junk Out of The Trunk: As you prepare to pack the car for your journeys, remember not to overload your car. Check the owner's manual for the maximum recommended load for the vehicle. An extra 100 pounds in the trunk reduces a typical car's fuel economy by 1-2 percent.

Know Your Oil: Use the grade of motor oil recommended by the vehicle manufacturer. The proper grade of motor oil can improve your gas mileage by 1-2 percent.

Tuning In: Before taking that long trip, visit a trusted professional and make sure your car is properly tuned. Depending on the kind of repair and how well it is performed, regular vehicle maintenance can improve gas mileage by an average of 4.1 percent.

Ease Up: Avoid quick or "jackrabbit" starts and stops. Aggressive driving wastes gas and can reduce your gas mileage by 33 percent on the highway and 5 percent in the city. Observe the speed limit; gas mileage decreases rapidly above 60 miles per hour.