John Nielsen: Hi! I'm John Nielsen with AAA's Approved Auto Repair. Maintaining the fluids in our vehicles engine is an important way to protect our investment and keep it reliable for the long term.

Now one of the first things that we think about is how to properly maintain the oil and there are several tips that we'll go through, but we're going to start with simply how often do we check the oil in the engine.

The engine oil should be checked at least once a month, and this is done by popping the hood and pulling the oil dipstick out, cleaning it, reinserting it back into the engine, removing it and reading the level. It's really not very complicated, and if you can't find the engine oil dipstick you can look in your owner's manual and it will point it out to you. And while you're in there, the owner's manual will tell you how often you should change your oil.

Now that's changed a lot in the last few years. It was once common to change your oil every 3000 miles, but modern engines have recommended change intervals that go anywhere from 5000-7500 miles or maybe even more. In fact, some engines today don't even make recommendations based on mileage, but rather use engine computers to determine how you've driven and under what environments to recommend the best maintenance interval for long engine life.

So now that we know how often to check and change our oil, the next thing to consider is what oil we're going to use when we do change it, and there are number of things to consider. And the first is going to be the oil weight; this is usually represented by two numbers separated by a W.

Once again, look in your owner's manual and look for the number that will be 0W-20, 5W-30, 10W-40, it will be a number like that. And it's important to use the manufacturer's recommended engine oil weight; because using oil that's too heavy can reduce your fuel economy or using an oil that's too light can provide too little engine protection.

The next thing to consider is its classification or certification. Now typically this is represented by an API letter designation, so you'll see an API starburst and two letters. The most modern oil is SG. There is a separate set of designations for diesel motors, but in recent years it's has been proliferation of proprietary engine oil designations and certifications. Perhaps the most recent is GM's requirement for the use of Dexos certified engine oil in all 2011 and newer model years.

So when you look in your owner's manual, make sure you understand not only the weight, but the designation and make sure the oil used in your engine meets those exact certifications. Failure to do that could impact the warranty of your engine.

The next consideration is pretty easy one, and that's going to be for the type of oil that we're using in the engine. Now we can use synthetic, semi-synthetic or even base stock oil. We've looked in the owner's manual a number of times and it will give us the exact recommendation that the manufacture has for maintaining our engine, if it require synthetic that's something that you definitely should use.

However, if your owner's manual recommends just the base oil you're fine using that. Now some people may want to use a semi-synthetic or fully synthetic, but you'll get maximum life and good performance out of using just the base stock oil.

So these are the things to consider when thinking about engine oil and following these tips can help you protect your engine for the longest period of time.