How to increase the gas mileage and power of your high mileage vehicle.

There are many different approaches you can take to restore lost power and gas mileage on you old vehicle. Feel free to try one or all of the following. I have tried them all and have found them to work for me.
1. Fuel Injector/Carburetor Cleaner. There are many different types out there. Many people say that these different chemicals do not do anything. I have found that they do work. Over time as you drive, gas and different imperfections in the gas will build up in your fuel line/fuel injectors/ carburetor. This will constrict the amount of gas that is injected into your engine thus limiting fuel economy and power. I recommend using one bottle at each gas fillup for three fillups then at every fillup that you see necessary.
2 Oil Additives. Once again, there are many different types, and many people people say they do not work. However, some are designed for high mileage vehicles and tackle specific problems you may be having. I use one that limits the amount of oil my 96 Corolla burns. I find that although it does not solve the problem, it does limit it. If i did not think it was worth my money, i would not be posting it here.
3. Tire Pressure. This step goes for all cars, not just cars with high mileage. Tire pressure is important for maintaining a smooth and efficient ride. You should fill your tires up the the pressure specified in your owner's manual or vehicle information sticker which is located in one of the front door's sile or in the glove box. Take caution, however, if the recommended tire pressure is above the max tire pressure(found on side of tire). It is better to have poor gas mileage than to risk a tire blowout.
4. Train Yourself to Drive Efficiently Install a MPG reader that tells you how efficiently your car is while you are driving it. Over time, you will learn how best to tackle the daily commute to work so to save gas. They will also come in hand if your check engine light comes on as some MPG readers double as a scan tool. You do not even need a MPG reader to drive efficiently on the highway. For most cars the sweet speed is 58mph. above this, your engine needs to work to hard to maintain a speed. Below this, and your engine is wasting power. Do not drive aggressively, and avoid hard stopping and fast accelerations. And on the highway, the key is to a constant speed, so use cruise every chance you can.
5. Keep Your Engine Clean. A very important step, there are many parts that can be done to improve MPG or power. First, inspect your air filter. Hold it up to the sun, if you can see through it, it is fine. If not replace if you wish. It used to be thought that a dirty filter hindered MPG. Now we know that it does not affect MPG but it does affect power or pickup. Next clean your PCV valve(if you have one) and hose using PCV cleaner This is a cheap spray that does wonders. Cleaning the PCV will allow for greater power when accelerating. And finally, as weird as it sounds, show your engine some love. It may seem strange, but a clean, and loved, car/engine just seems to drive nicer and more efficiently.

Remember, a car with bad gas mileage can be turned around and made as efficient as the day it came off the line. All you need is some know-how, patience, and determination. Cheers to safe, and efficient driving.