Check your PCV valve: not every car has this, but if you have an older car, you might. It is the positive crankcase ventilation valve that that helps control emissions. This valve has a unique function, and for proper engine function it has to be working right. It is going to circulate partially burned gases from the engine's crankcase to the combustion chamber. This valve should be changed every 30,000 miles. It is going to improve fuel efficiency, and prevent sludge and grime buildup in your engine, that may lead to corrosion, etc.

Change spark plugs: This is another thing that should be done every 30,000-40,000 miles, and will help improve fuel mileage and engine performance. Some spark plugs can be used for 50,000 miles. If you switch them frequently your car will run better.

Check your hoses: A broken hose ca lead to a lot of trouble. One of the best things you can do is check your hoses regularly. If your car is off and cool, then squeeze the hoses, if they are hard or crunch at all, you will want to replace them. If they are too soft or too sticky, you will want to replace them as well. Look for bulges or collapsed sections, etc. If the hose has any problems, you will want to replace it, as it can overheat, explode, etc, and can cause problems in your car. For example, a hose is used for power brakes. A hose is used for cruise control. There are all kinds of hoses in your car, and many are crucial for proper car function. So, make sure you check them and replace them when necessary.

How is your drive-belt tension? Your drive belt or belts should be checked monthly, as a drive belt that breaks can cause real engine damage and cost you thousands in repairs. Make sure they are not too tight, as this can wear out the bearings in the components like your AC compressor, or your water pump. If your belts are too lose they may wear out faster. You want to test the tension before you start the car. So, what is too tight? What is too lose? How do you test your drive belt tension? Well, start by finding a ruler, then press the center of the belt's longest exposed run, if you can depress it ½ to an inch, it is good, more means it is too lose, less means it is too tight.

Wash your engine: You want to do this every year or two. The reason you should clean it is because it will be far easier to find leaks and problems. You can use a detergent, etc.