HOUSTON --We're all looking for a way to save gas as the prices go higher. There are some obvious things you should be doing to get better gas mileage, like keeping your tires properly inflated and using the recommended grade of motor oil. But some other tips are not as obvious. With a fleet of 12 Chevys, Tom Limon with Needcomputerhelp.com needs to make sure his cars are fuel efficient. "We do on site computer support. We basically work out of our cars; our car is our office," Limon said. So he brings his vehicles to Upland Automotive. Jay Wilson with Upland Automotive says you must get your oil changed every 3,000 to 5,000 miles depending on your owner's manual, but on top of that add an oil additive. "It reduces internal frictions a lot and you can add one or two miles per gallon," Wilson said. Another tip on keeping your fuel mileage up is to make sure your air filter is clean. "The cleaner it is the more efficient, the better gas mileage you get," he said. Wilson says in typical Houston driving conditions, your air filter should be changed every second or third oil change. Another tip to better gas mileage: decarbonation of your engine. Wilson says over time gas creates a lot of carbon build up on internal engine parts and causes your car to run less efficient. Take for example a cylinder head that's never been cleaned. "You can see the carbon accumulation in the cylinders. This one has never been cleaned; it's pretty excessive. So in this case, it was so much carbon that it caused the valve to bend," Wilson said. You should decarbonize your engine every 25,000 to 30,000 miles. Here's a tip for those who have high mileage cars: it may be time to replace your spark plugs. "Over time, the gap at the very end here becomes excessive, and the more excessive it becomes, the less fuel mileage you are going to get. It takes longer for that spark to jump from one tip to the next," Wilson said. Wilson says you should look to replace your spark plugs at around 90,000 miles. Something else that should be replaced after 90,000 miles is your timing belt. "This timing belt keeps the cam shaft and crank shafts in time together. If this timing belt were to stretch, you're going to lose your fuel economy right away," he said. For Limon, keeping his cars in tip top shape means a huge savings in gas money. "Gas is one of the biggest expenses and we need to make sure our tires are rotated properly, the air filter and the oil is changed on a regular basis and we need to do that religiously," Limon said. Here are a couple more ways to be fuel efficient: clean out your trunk or back seat since a heavier car burns more fuel. Instead of running the AC on a low, medium or high setting, if you have the circulating air option, use that instead.