Changing Your Engine Oil: Why, When, What-All Of Your Questions Answered

Changing your vehicle's oil is one of the most important things you can do to avoid bringing large bags of money to your auto repair technician later on.

Oil is a magical substance. Oil is used in everything from plastics to fertilizers to fuel and, of course, lubrication. When it comes to your engine, oil is the key to making it last. Without lubrication, the metal parts would just grind together and seize up in a matter of minutes.

So, what is it that engine oil specifically does for your car?
1. Keeps the engine cooler. It does this as a matter of design. The design of the engine and the layout of the oil system allows it to actually cool and draw heat from the engine. It does this because the oil collects in the oil pan. The oil pan is located at the bottom of the engine. As the car is moving, air rushes by the oil pan. The cooled oil then circulates up through the engine and siphons off some of the heat being produced. A car still needs a coolant system, but oil definitely plays a part in the process.
2. Oil in your engine cuts down on friction. Oil is a lubricant. You only need to rub it between your fingers to know this. (Try rubbing your palms together as fast as you can for one minute-how does it feel? Now, put hand lotion between those palms, and try it again-notice the difference? Your car’s metal parts react the same way).

The engine is essentially a mechanism of controlled explosions. The energy produced in the explosion propels metal parts. Oil sits between those parts and cuts down on the wear and tear caused by the back and forth movement. It is this lubrication that keeps the engine parts from heating up and melting into one block of metal goop.

Why do I have to change my engine oil?
Oil is amazing, but even oil will begin to break down after a while. Modern car engine oil is particularly helpful to cars because it contains detergent. What does detergent do? It breaks down the gunk found in an engine. This means that you can effectively take an old car and "revitalize" the internal engine parts by using modern oil. The oil will effectively clean up the gunk within the engine and help the engine run cooler. A cooler running engine is an engine that lasts longer. That means fewer repairs and less money spent.

• Oil undergoes thermal breakdown due to high operating temperature. When this occurs, the oil becomes less effective as a lubricant. And without a good lubricant, parts of the engine rub together and wear each other out.
• Oil also contains additives that have the ability to neutralize acids. Over time, these additives get used up and stop being effective.
• Finally, oil can absorb water, dust and combustion byproducts and also hold them in suspension. Eventually, the oil gets saturated with this stuff and can't absorb any more. Then that stuff remains in the engine and can cause corrosion.

The clearances between metal engine parts can be as little is .0010". The oil keeps the metal parts from touching. But even with oil between the metal parts, the spinning creates heat. In addition to lubricating the parts, the oil also carries the heat away.

Does it really matter when I get my oil changed?
There is much discussion about exactly when engine oil gets old and how often it should be replaced with new oil. Because there are many factors at work — how you drive, the condition and age of the engine, the external environment you drive in, and stop-and-go versus highway driving — it's an inexact science. Owner's manual recommendations for oil and filter changes vary from 3,000 to 10,000 miles, while most manuals say 7,500 miles.

We recommend that you change your oil and filter every 5,000 miles. That may be too soon for many people and too late for a few, but for the vast majority, 5,000-mile oil changes will help your engine last a long, long time-several hundred thousand miles.
You may want to consider changing your oil more frequently (3,000-4,000 miles) if:

• You drive like you are in NASCAR: jackrabbit starts, heavy acceleration or high-speed driving;
• You live in Utah, where the climate gets extremely hot and cold;
• You often drive on dirt roads;
• Your engine is old and burns oil;
• You frequently carry, pull or haul heavy loads (from your children’s soccer team to your prized horses, boat or camper trailer).

But the really important benefit to changing your oil every 3,000-4,000 miles is to have drivers routinely visiting a mechanic every 3,000 miles or three months to do a check up on their cars.

Most drivers don't even open the hood anymore-or check around their car or truck for obvious repair signs-a tire that is showing steel, a water hose swollen and about to bust, a leaking radiator, expired state inspection stickers, etc., etc., etc. In the old, old days, gas stations had attendants to check these every gas tank fill up (and they would pump your gas, wash your windows (see the movie “Back To The Future”-the first episode). With today’s “gas and goodie” stores, nobody checks those things-not even you!

Since the average American driver drives 12,000 miles a year, that is 3 or 4 oil changes a year. At $35 an oil change, that's about $100 a year to have your cars looked over and make sure things are okay. Now, compare that to a tow bill...the alternate price you'd pay if that radiator hose bursts on you in the summer, or tire blows on an icy road in the winter, leaving you on the side of the road with a car load of kids, groceries, missed appointments, and headache medicine.

What happens if I don’t change my oil?
Your engine won't last as long as it could-plain and simple. Oil serves many crucial functions, and clean oil performs those functions better than dirty oil.

The benefits of oil changes are not so great as the drawbacks of not getting your oil changed, which are catastrophic. While you do increase the life of your engine and keep your horsepower maximized by getting your oil changed regularly, these are not as significant as the problems that can arise if you do not change your oil when it is recommended to do so. First, not changing your oil often enough can cause significant damage to your engine, as the oil is necessary to keep all of the moving parts lubricated. By not having enough oil or by using oil that has outlived its usefulness (is filled with dirt or has low viscosity), you run the risk of allowing parts to not work as efficiently as they possibly could.

Squeeze too many miles out of your oil and you will find black gooey sludge at the bottom of your engine. Since the anti-friction additives will be gone, you'll see burned oil on all the engine parts (just like burned butter in a frying pan).

In the long run, such parts grinding together without lubrication in such a stressful environment as an internal combustion engine could eventually lead to such parts fusing together, jamming up or altogether failing. This is catastrophic to your engine, as the engine could simply stop working or actually explode if enough parts refuse to work.

If you break down the engine of a car that has not had its oil changed regularly, you will see what essentially looks like a scorched earth surface. Everything will be black, and there'll be balls of burnt oil everywhere. It's generally known as gunk. Gunk kills cars. It makes it difficult for parts to work efficiently, but it also acts as an insulator that causes the engine to heat up-and heat kills engines.

Can I change my own engine oil?
Sure, there is no law against it. That is, until you try and bury your old oil in your backyard. Oil disposal has become a hot issue in the last decade or so. Remember, it is illegal to dispose of used motor oil improperly. The EPA now levies a huge fine ( yes, HUGE-as much as six figures) for improper or illegal oil disposal. The days of digging a hole in the back yard and pouring dirty oil into it are long gone.

Are you ready to properly dispose of your used engine oil?  Smith’s, Harmon’s, Target and convenient stores sell motor oil-but they do not accept your used oil back. You will have to find auto parts stores (Auto Zone, Pep Boys, O’Reilly, Wal-Mart) who will accept old oil from do-it-yourselfers. (And, make sure it is in a container that will not spill inside your vehicle-that would blow all of your well intended DIY savings!)

Answering Yes to the questions below means changing your engine oil will not become an all day marathon project:

• Do you enjoy tinkering around the garage?
• Do you own your own hand tools?
• Are you okay with getting a little grease under your fingernails?
• I've fixed things on my car that involve removing more than 5 bolts.
• I've built a time machine out of wood.

Why do I have to check my oil level between oil changes?
Yes, you need to check the oil level every few hundred miles. With your car parked on a level surface, remove the oil dipstick, wipe it off on one of the fast food napkins you have stuffed in the glove compartment, and then reinsert it. Remove it again, and check the oil level.

Ideally, it should be right at the full mark. If it's at or below the add mark, that means you're a quart low and should add a quart of oil to the crankcase. If it's in between the two marks, you can add part of a quart to bring it up to the full mark (the distance between add and full represents a quart, so use that to estimate how much of a quart you need).

At some point, every engine starts to burn oil. Get in the habit of checking the oil from time to time, and you just might avoid having your engine melt down one day.

If you regularly run low on oil, be sure to report it to your mechanic. You may have a leak or may be burning oil — signs that you might be gearing up for a major boat payment to your mechanic.

Be careful not to overfill your car's crankcase with oil. If you put in too much oil, the engine's crankshaft can actually come in contact with the oil. And because the crankshaft is turning at several thousand revolutions per minute, it can quickly whip your oil into a froth — like the steamed milk that sits on the top of your Starbucks cappuccino. Why is that bad? Well, the oil pump can't pump froth very well, and as a result, it can't get oil to the parts of the engine that need lubrication. The result? An unplanned and expensive visit to your auto mechanic.

In conclusion, the combined effect of leaving dirty oil around a car’s engine can significantly decrease the life of vehicles while also making the vehicles less safe to drive. Basically, regular oil changes as part of routine car maintenance plays an important part in accident prevention.