Manufacturer's recommendations are once every 3,000 to 7,500 miles, depending on the car. Most people change it once every 6,000 miles. Conventional wisdom says that changing more often is better, but some experts now disagree. We recommend you do it every 3000 miles

Changing oil can be a messy job, so wear old clothes and have some hand cleaner handy. Make sure that your car is parked on a level grade, rather than on any sort of hill or inclined driveway. You'll need some place to take your old oil, so call a few gas stations or town hall to find out who recycles used oil. Always Recycle !

Warm oil drains more easily than cold oil, so run your engine for just a few minutes before you start. But be very careful: Don't let the oil get too hot, as some may splash on you.

Always make sure that you're on level ground. Set the metal ramps in front of your front tires, and drive your car up onto them. It can help to have a friend around to tell you when to stop.

Set your emergency brake. If you have a manual transmission, put the car in first gear. If you have an automatic, set it to Park. Place the wheel blocks under the rear wheels to prevent any chance of the car rolling back.

Drain the old oil

Watch out for hot oil! It's not a bad idea to wear safety glasses or even prescription glasses.

Take your wrench and shallow pan and crawl under the car. Find the oil plug under the engine block that unscrews on the underside of the oil pan. Place the shallow pan under the plug and unscrew the plug (counterclockwise) with the wrench. (If the wrench slips and starts to round off the bolt head, try a socket wrench instead.) The oil will stream out rapidly, so be careful. Chances are, the plug will fall into the pan along with the oil. Don't worry when it happens.

When all the oil has drained into the pan, fish out the plug (here's where rubber gloves come in handy) and screw it back in. Tighten it firmly, but not so hard that you strip the threads.

Change the filter

Always change the filter whenever you change the oil. Clean oil + a dirty filter = dirty oil. This is not a good thing.

You'll be able to access the old filter from either above or below the car. Place the oil filter wrench around the filter's body. It will tighten itself up when you turn the wrench counterclockwise to remove the oil filter. The old filter may stick initially, but will then unscrew easily. Unscrew it completely and carefully put it aside. It will be full of oil. Dip your fingertip in the old oil (convenient) or take a few drops from a new quart of oil (cleaner). Use it to lubricate the circular edge of the new filter, where it will contact the metal engine surface. Screw the new filter in with your hand, and tighten it firmly without overtightening--one quarter turn after snug.

Finish it up

All you have to do is add the new oil and clean up.

On top of the engine you'll find a knob that says "oil." Unscrew it and pour in the amount and type of oil recommended for your car. Look in your manual for the location of the knob if it's not obvious. Save the bottles for the disposal of the old oil. Screw the knob back on and wipe the area clean with the rag. Close the hood and start the engine. With the engine running, carefully check around the filter for any leaks. A leak will appear as some seepage at the oil filter connection or on the filter. If there is a leak, tighten up the oil filter a little more. If no leaks are found, back the car off of the ramps.

Pour the oil out of the pan, and using the funnel, transfer it to the empty oil bottles or milk containers. Take the used oil to the motor oil recycler that you found (you did find one, right?). Your ready to go for the next 3000 miles.