Oil Change Every 3000 Miles - Good Advice or Just a Sales Pitch?

ost people are told by their mechanics that the oil in their car needs to be changed every 3,000 miles. But is that really necessary? Can the oil in your car possibly last longer than 3,000, 5,000 or even 7,000 miles? Somehow changing the oil at 3,000 miles feels safe and reassuring of no mechanical breakdowns.

There are only a few basic reasons why it is necessary to change your oil, and they all, in the end, have to do with decreased protection of your engine and decreased performance. If these elements can be minimized, then there would be little or no reason to change the oil.

Under "ideal" driving conditions, you could extend the period between changes to as much as 7500 miles. A new engine with little or no wear can probably get by on 7500-mile oil changes. However, how do we determine ideal conditions? What many of us consider to be ideal conditions, your owner’s manual describes as “severe” conditions. These include: stop-and-go driving; frequent short trips (under 10 miles); wet weather driving; hot weather driving (above 90 degrees F); cold weather driving (below 40 degrees F); trailer towing; and long periods of idling.

We can better appreciate the need for changing the oil every 3,000 miles if we understand how oil breaks down in our car. The most significant difference from one oil to another is how quickly breakdown occurs. Although there are many factors that contribute to the breakdown, heat is one of the most important. As an engine accumulates miles, it dumps more unburned fuel into the crankcase, which dilutes the oil. This causes the oil to break down.

There are two types of oil, petroleum and synthetic. The first major difference between petroleum and synthetic oil is heat tolerance. Petroleum oil begins to break-down almost immediately. A high quality synthetic, on the other hand, can last for many thousands of miles without any significant reduction in performance or protection characteristics.

Today's engines are expected to put out more power from a smaller size and with less oil than engines of the past. Therefore, the engines run much hotter than they used to. That puts an increased burden on the oil.

It’s important to note that synthetics do a much better job of "cooling" engine components during operation. Because of their unique flow characteristics, engine components are likely to run 10 to 30 degrees cooler than with petroleum oils. This is important, because the hotter the components in your engine get, the more quickly they break down.

Do Additives Help Your Engine?

It is true that the additives in many oils begin breaking down after only a few thousand miles. Additionally, there are different quality "grades" of additives as well as different quality grades of just about any other product out in the market today. You also need to consider that there are different combinations of additives that tend to work for better and for longer when combined than when used individually.

Stating that additives in oil die after 3,000 miles is no different than saying that automobile tires only last for 30,000 miles. We all know that there are plenty of tires on the market that do indeed last for only 30,000 miles, but we also know that there are many tires on the market nowadays that will last over 75,000 miles.

The same holds true for motor oils. Many oil companies are using the same additives in their oils as all of the other companies because they are cheap. That's why the oil costs less. You get what you pay for.

Most people who use synthetic oil believe it gives them piece of mind. They know that when 20,000 miles rolls around, they still have a few thousand miles left to find time to change the oil. However, unless you have a new car, synthetic oil is not recommended.

Finally, don’t forget to change your filter every time you change your oil – it only costs $2 or $3. It doesn’t make any sense to change the oil just to have it re-contaminated by trace elements in the filter.

Also see

Your Car's Mechanical Condition

Best Auto Repair Manuals for the Do-It-Yourselfer -are you the fix-it-yourself type? Find great sources for your manuals.

Don't Let your Mechanic Take you to the Cleaners -more tips for choosing a trustworthy mechanic.

Rebuilt vs. Remanufactured Engines -Your engine has failed and must be replaced. Which type do you choose?

Change Your Oil Once a Year or Every 35000 Miles! -learn about synthetic oil and it's advantages for you.

This webpage is brought to you for general information purposes only and there are no warranties as to accuracy, completeness, or results obtained from any information posted on this or any linked website.

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