Services > Maintenance > Oil Changes

10 Truths About Oil

By Kathryn & Sybren van der Pol

Copyright 2013 ALL RIGHTS RESERVED

The owners of Adolf Hoepfl Garage are writing a book about automotive maintenance including hybrids. Here is a sample chapter.

  • The truth about oil is in general we don’t change our oil frequently enough.
  • Changing oil on a faithful basis is the best preventive medicine for the health of our engine.
  • Oils have greatly improved in the past 10 years.
  • There are substandard oils on the market.
  • Many manufacturers recommend oil change intervals beyond what is in the car’s best interest.
  • Oil changes are the easiest and yet most dangerous operation performed on a vehicle.
  • Oil filters are just as important as the quality of the oil.
  • Synthetic oil changes are going to be the norm in the near future.
  • Cars can burn a quart of oil every 1000 to 1500 miles.
  • It is vital to your engine health to check your oil level every time you fill up for gas.

This chapter is about education. Many people consider oil changes a necessary evil. They look for those $14.99 oil change specials on the back of their grocery receipts and do not realize that they may have inadvertently “fed” their motor a very unhealthy diet that may shorten their vehicle’s life expectancy.

After reading this chapter on oil, you will become an oil change nutritionist and preach the good health benefits to all your family and friends on the importance of a proper interval and an acceptable quality oil and filter.

Well let’s examine each of these “truths” one at a time.

The truth about oil is we don’t change our oil frequently enough

In the old days, knowing the correct oil change interval was easy. The universal wisdom was cars needed oil changes every 3,000 miles. Period. In our family, we were taught if the mileage was evenly divisible by 3000, it was oil change time. This was before the invention of oil change stickers. The only exception to this iron clad rule were those rare cars that did a lot of highway driving.

According to AAA of Texas, 25% of the cars on the road exceed the manufacturer’s recommended oil change interval by 500 to 1000 miles. This means that even with the better oils and better engines, drivers are going further on the oil than the manufacturers intended.

At our shop, about once every couple months, we are replacing motors because the owner forgot to change his oil or thought that the $14.95 oil change was being kind enough to his car or he let the vehicle run low on oil too many times. More on that issue in a moment.

If you are reading this book, we are sure you are not that kind of car owner, but you might know someone who is. Buy this book for your friend. It will help!

Today, manufacturers have recommended oil change intervals as small as 3,000 miles and as great as 15,000 miles (BMWs!). Combine that degree of variation with the myriad of oil products available on the market, such as Exxon’s Extended Mileage Oil, Shell Rotella or Castrol Oil and all these oil companies claim their product is the best, what is the poor driver supposed to do? What happened to those good old-fashioned iron clad rules?

So, how often should you change your oil? Well, it depends.

The first question to ask is do you plan to keep your car? If the answer is no, then use the cheapest oil you can buy, go 7,000 to 10,000 miles between oil changes, and sell it before it reaches 75,000 miles. You can put this book down and go do something else with your day.

If you are still reading, congratulations! You are someone who wants to keep their car and learn how to take good care of it so it will last.

So, what is a good car owner to do?

There are two schedules in your owner’s manual. One is usually called “severe” service and the other is called “normal” service. Often, the manufacturer leaves it to you to decide what is severe and what is normal. So, here are some questions:

  • Do you drive in hot weather over 90F?
  • Do you drive in extreme humidity?
  • Do you drive in stop and go traffic?
  • Do you take shorter trips than five miles?
  • Do you drive at high speed on the highway?
  • Do you drive in extreme cold weather 10F?
  • Do you tow a trailer or haul heavy materials?

If you do any of the above, congratulations. You drive under “severe” conditions and that’s the schedule you should follow.

Changing oil on a faithful basis is the best preventive medicine for the health of our engine.

If your vehicle is a 2008 or older, we believe you should stick to the 3,000 mile oil change interval. You can’t hurt your car and can only help your motor remain clean by following this schedule.

Newer than 2008

If your vehicle is 2008 or newer, you probably can go further than 3,000 miles on an oil change. Of course, if you want to stick to a 3,000 mile interval, you certainly are not hurting your car to do so. But it is true that the oils are better (see next section) and the motors are cleaner running. A good rule of thumb: Never go further than the manufacturer’s recommendations in your owner’s manual. That’s absolute maximum mileage.

So, here is our guideline based on oil type.

  • Conventional oil: 3,000 miles
  • Synthetic blend: 4,000 miles
  • Full synthetic: 5,000 miles
  • Conventional oil with BG Products: 5,000 miles
  • Synthetic oil with BG Products: 7,500 miles
  • Dexos: 7,500 miles

Explanations

I’ve heard of Synthetic blends, but what is it exactly?

Synthetic blend oils are primarily conventional oils with 5% to 15% synthetic oil blended in. Some shops will use a synthetic blend oil change as a mid-price option between conventional oil and full synthetic. At Adolf Hoepfl Garage, we do not use conventional oil for a standard oil change. All of our “regular” oil changes use a synthetic blend oil produced by a local Houston company.

How are synthetic oils different from conventional oils?

Synthetic Oil is conventional oil that has been extremely well filtered and has special chemicals added to it to enhance its performance. There is no industry standard definition of what qualifies as a synthetic oil. Court cases have been won and lost because of the lack of a specific definition for synthetic. Synthetic oil changes cost 20% to 40% more than a conventional oil change. The most recognized synthetic oil on the market is Exxon’s Mobil One.

We will explain BG Products a little bit later in the book, but if you want to jump to that section now, click here.

Dexos is a synthetic oil licensed by General Motors for some of their 2012 or newer cars.

Of course synthetic oil changes cost more but the benefit is you can drive further. Sit down and do a cost analysis. Here is a simple calculation to do right now. Later on in this book, we will talk more about budgeting for maintenance.

If you drove a 2005 vehicle 15,000 miles per year, how much would five oil changes cost for conventional oil changes as compared to three full synthetic oil changes?

If you do five oil changes for $38.00 each, the total costs equals $190.00.

Three full synthetic oil changes at $60.00? $180.00.

Does the math surprise you? It might actually save you money to use synthetic oil. Of course, oil change prices vary greatly during the time of year, the market price of oil, and region of the country.

But, what if you drive less than 5,000 miles per year? You still need to consider the effects of time on your oil. Change your oil at least every six to eight months. Oil breaks down and becomes contaminated over time and not just use. Oil ages just sitting inside your motor. It is also a good idea to have a qualified technician check over your car twice a year just to make sure your tires are inflated, your fluids are full and nothing is leaking.

Is changing oil bad for the environment? No!

You may have read articles about environmentalists who claim the 3,000 oil change interval is a dinosaur practice. They may even try to persuade you that you are polluting the environment by changing your oil that often. Just remember these environmentalists are not auto technicians, and they are not even right. By extending oil changes too far, oil becomes highly contaminated with dirt particles. These particles in the oil make it less slippery and the oil can start “pitting” metal parts and this causes “wear and tear.” In addition, contaminants create deposits in the bottom of the motor that never drain out and accumulate over time. This is the famous sludge. On top of this, contaminants damage rubber seals, causing the potential for oil leaks.

Dirty running motors burn oil, leak oil and cause real harm to our environment. And most poorly running vehicles become that way through neglect. A common area of neglect is failure to change oil frequently enough.

These environmentalists are not the engineers who designed your motor; nor are they the oil recyclers who purchase used oil, filter it and resell it; nor are they oil manufacturers who work on making ever better quality lubricants; most importantly, they are not the auto technicians who fix the cars that come in as a result of failure of proper maintenance.

Environmentalists are not car experts and are not interested in making your car last as long as possible. In fact, many environmentalists would like to ban cars. So, don’t feel guilty about changing your oil.

So, why do they claim that extending oil changes is good for the environment? They are looking at it statistically. They are imagining that if everyone changed their oil every 10,000 miles instead of 3,000 miles think how much less oil cars would need! They use statistics to build an argument to change policy. Their research fails to take into account that while we would reduce the amount of oil we use for oil changes, we would more than make up for that in repair costs and more polluting vehicles. Oil is not wasted. Just ask the oil recyclers.

Oils have greatly improved in the past 10 years

Oil technology marches forward. Oil has more ratings and standards than we will be able to discuss here. Engines are lighter, run hotter, and are more fuel efficient. Better quality oil makes these improvements possible. Especially since engines are designed to run hotter, using an excellent lubricant is essential. It truly buys peace of mind. More models are requiring full synthetic oils.

Here is a diagram that shows you the latest grade for motor oil called GF5. It replaced GF4 in 2011.

You can see that there are many properties that both GF4 and GF5 oils have that make them far superior to the oils that our parents were familiar with. Oils have to do a lot more work. They have to

  • Lubricate the moving parts of the engine
  • Improve fuel economy
  • Keep the engine clean
  • Cool the motor
  • Maintain the suppleness of seals
  • Reduce emissions

Now you may be asking yourself. Can oil really do all that? Yes, it can, but only if it has not deteriorated and is the right type.

There are substandard oils on the market

To measure whether oil has all these properties, ILSAC, the International Lubricant Specification Advisory Committee tests the oil and certifies it. In other words, this is the international organization that makes sure oil meets the standards. It is a very expensive process for any oil company to have their oil certified by ILSAC and can cost upwards of $40,000. So, some smaller oil companies may sell products that actually meet the new standards but are not certified because they have not paid for the testing. These may be smaller oil companies that sell for a local market. On the other hand, there are many sub-standard oils on the market that are mass produced and sold in convenience stores, truck stops, even some repair shops (Beware those $14.95 oil changes! Read the fine print.) These oils will not be certified either. They may be recycled oil that has been filtered, or sad to say, just crappy oil. This is why you want to be sure that what is in the bottle is good for your car.

In the United States, the American Petroleum Institute (API) licenses the oil that is distributed. They audit their members’ oil and require them to monitor the “chain of custody” to insure that the product is not altered from the manufacturer to the end user.

There is such a concern in the industry about substandard oils that the American Petroleum Institute has begun a public relations campaign called MOM: Motor Oil Matters. Here is what they say:

How to Identify Quality Motor Oil

When choosing oil for your vehicle, always look or ask for API-licensed oil. API has made it easy to find these oils: licensed oils display one or both of the API motor oil quality marks—the API Service Symbol “Donut” and the Certification Mark “Starburst.” These marks are part of API’s Engine Oil Licensing and Certification System (EOLCS), a voluntary licensing and certification program that authorizes engine oil marketers meeting API requirements to display the API quality marks.

API Service Symbol “Donut”

The API “Donut” identifies oils that meet current API engine oil standards. It includes the SAE (Society of Automotive Engineers) viscosity grade of the oil, API standards met by the oil, and other important performance parameters.

  • The top of the “Donut” displays the motor oil’s API performance standard. The letter “S” followed by another letter (API SN) refers to oil suitable for gasoline engines, and the letter “C” followed by another letter and number (API CJ-4) refers to oil suitable for diesel engines.
  • The center of the “Donut” shows the motor oil’s viscosity grade. Viscosity is the measure of an oil’s ability to flow at certain temperatures.
  • The bottom of the “Donut” tells whether the motor oil has resource-conserving properties when compared with a reference oil in an engine test. Motor oils labeled as “Resource Conserving” have passed this test.

API Certification Mark “Starburst”

The API “Starburst” signifies that the oil meets the latest International Lubricant Specification Advisory Committee (ILSAC) standard.

Oil Weight

What do the different weights of oil mean? I’m sure you’ve heard of 10W30. The numbers have to do with viscosity, in other words how thick is the oil. Think runny ketchup versus thick honey. The higher the number, the thicker the oil or its viscosity. The W stands for weight. There are two numbers. The first number measures the oil thickness for starting-the-engine temperature (100F). Yes! That’s still hot. The second number measures the viscosity at a little above the normal engine operating temperature (212F.) Oil has different viscosities depending on its temperature. The reason the viscosity changes is because polymers (plastics) are added to the oil that thicken it up when the oil is hotter—at least to a certain point (212 F). Past 212 F, the polymers can fail and then the oil becomes really thin really fast. When oil fails completely, it turns to plastic sludge.

How Stuff Works says, “Think of a 20W50 as a 20 weight oil that will not thin more than a 50 weight would when hot.” A 20W50 is a relatively thick oil. The traditional standard for oil has been 10W30.

In the old days, to calculate viscosity, one measured how long it took for a drop of oil at a certain temperature to roll down a slanted piece of metal. In the modern lab, they have fancy equipment, such as the Capillary Tube Viscometer that basically sucks the oil at the precise temperature in a glass tube and measures the viscosity when the suction is released.

It is important to read your owner’s manual and know what the recommended weight is for your car. Engines are built to much more precise specifications than in the old days and the clearances are so small that using the wrong weight of oil could cause harm. It is important to ask your repair shop what type of oil they use and what its weight is.

Now, think about this. If you live in a cold climate and your owner’s manual says use a 5W20, that means that in December, your car wants a very thin oil to start your engine moving but once the engine is running at normal operating temperature it becomes slightly thicker. A 5W20 is thinner than a 10W30. Why do manufacturers use such thin oils? These new lower weight oils improve gas mileage more so in very cold weather. If you used a 10W30 in the winter time, you would lose some fuel economy. In other cases, using a heavy oil could cause problems. A hybrid Honda Insight which is supposed to have 0W20 will not start in the winter time if the oil is too thick.

It is also important to know that at high temperatures, thicker weight oils provide more protection. If you are driving in 100F plus degree weather for extended periods of time, a 0W20 oil may become too thin for your engine needs and you may want a 10W30 oil. The hotter the weather, the harder the oil works and the quicker it breaks down. Remember, those many mers in the polymers become a glunk of junk when your engine is overheated.

Many manufacturers recommend oil change intervals beyond what is in the car’s best interest

Recently, General Motors was in the news. The headline in Motor Trends magazine said, “GM Shortens Oil Change Interval Warnings for 779,000 Vehicles.” They were having to replace too many engine parts because their oil change intervals were too long. Their spokesman stressed that this warning was independent of the type of oil used. In another example, BMW was recommending 15,000 miles between oil change intervals. Why would car manufacturers do this? Three reasons.

First, the government requires manufacturers to calculate the maintenance costs of a car’s 100,000 mile life span when bidding on selling or leasing vehicles to the government. If the oil change interval was extended, that would reduce the cost of maintenance and make the car appear more economical to government purchasing agents.

Second, manufacturers are in the business of selling cars. The chief goal is to have a perfectly running vehicle during the warranty period. After the warranty period, manufacturers hope that you will buy another new car. But if you actually took care of your car, it might last 500,000 miles. If everyone did what we recommended in this book, manufacturers would sell fewer cars.

Finally, read this comment from a BMW owner. “BMW says I can go 15 k miles between oil changes, so their free maintenance consists of two oil changes and that’s it! If you don’t believe me go 15k, and send your oil to Blackstone labs for analysis. It’s very cheap, or you could just Google it, and see what other people have discovered. You can go 6-7k now with improved oil, and gasoline but that’s about it without having too much metal content suspended in the oil. If you plan to trade your car before 100K miles, you can go 20K intervals, but if you want your car to last as long as possible I would not go past 7Kmiles. It’s no coincidence BMW doubled their change interval, and made other fluids’ “lifetime” when they introduced “free maintenance.”

You are now wiser than the average bear when it comes to car care.

Oil changes are the easiest and yet most dangerous operation performed on a vehicle

Now that you have read this much about oil, you know how important it is to change it faithfully at a proper interval and to use the right type and weight of oil for the vehicle and the conditions that you are driving in. Unfortunately, there are many horror stories of customers going in for an oil change and having it done so incompetently that the motor locks up within a few hundred yards of the lube center.

Lube techs can make all kinds of mistakes such as stripping drain plug, not tightening the oil filter, using the wrong size filter, and even forgetting to put fresh oil back into the motor after it’s drained. It is little comfort that the employee will lose his job for his negligence. This is a headache for the company and the consumer. Any one of these mistakes can result in total engine failure in less than five minutes.

It is important to find a reliable place to service your vehicle. Many lube centers employ minimum wage workers who have little experience or have too little oversight. Find out if the place you use has an ASE certified technician changing your oil. That is not a guarantee that mistakes can’t happen, but it is less likely. ASE certified technicians must have a minimum of two years’ experience and take a rather rigorous examination. They are usually higher paid so you may not always find a great discount at shops that hire ASE certified technicians, but you should expect a more careful look at your car and a higher degree of competence.

Oil filters are just as important as the quality of the oil

There are good filters and cheap filters. The reason the better filter is worth it is because you will get the dirt out of your oil. If you are driving 5,000 to 7,000 miles between oil changes, this becomes critical. When you have a coupon for a $9.95 oil change, what type of filter do you think you are getting? The repair facility paid about a $1.00 for that filter.

You should expect to pay $8.00 to $15.00 for a decent quality filter. Sometimes, it may be a little less, if the repair shop offers an oil change for a package price.

Some oil filters have check valves. Toyotas, Subarus, and Mazdas need those check valves because it keeps all the oil from running down to the bottom of the motor when the car is turned off. Cheap filters don’t have check valves so what happens is when you start one of those cars that needs it, you are starting it without any oil circulating in the top of your motor. Over time, this shortens the engine’s life.

Remember, oil changes are your least expensive maintenance expense. Cutting corners does not save you money in the long run. If your vehicle has good quality oil and filters, you will prevent major engine repairs and extend the life of your vehicle.

Synthetic oil changes are going to be the norm in the near future

Virtually all cars produced after 2012 will require synthetic oil. Check your owner’s manual. Just remember that you may be changing your oil less frequently, but you will be paying more for each oil change.

Now the question comes up at our shop, “Can I go from a conventional oil to a synthetic oil?” The answer is yes. There is no harm switching to a better oil no matter the age of your vehicle. Synthetic oil will blend perfectly fine with a conventional oil provided that the oils have the API Sunburst logo.

Cars can burn a quart of oil every 1000 to 1500 miles so It is vital to your engine health to check your oil level every other time you fill up for gas.

According to a General Motors Technician Service Bulletin, it is not considered abnormal for low mileage cars (less than 50,000 miles) to burn a quart of oil in 2000 miles. The same bulletin states that high duty pick-up trucks and high performance cars can burn a quart every 500 miles. How can that be if oils are better and oil change intervals are longer?

Vehicles have always burned oil but burn less oil than in the past. A little bit of oil is always getting past the valves and lubricating the cylinders. So, it is normal for a vehicle to lose a quart of oil every 3,000 miles and it is replaced with a quart of contaminants (gasoline, carbon, etc.).

Our coddling culture of convenience has given us a false sense of security. Full-service gas stations are rare. In the past, the gas station attendant was a reminder of the importance of checking regularly under the hood. Our culture has lost that. In addition, motors are covered with shields and run by computers so we feel less confident that we can manage what’s “under the hood.”

Now that you are empowered, check your oil. Don’t let your vehicle become a casualty of having only two quarts in the crankcase. The issue of low capacity in oil crankcase is a serious problem. Remember, it’s a fact. Cars and trucks burn oil. In fact, if you are doing some long distance driving, carry an extra quart in your trunk.

At our company, it is our policy to check the oil on every vehicle that comes into our shop regardless of why it’s there. Low capacity is the newest car disease.

So, how bad could it be? Let’s do some math. If your vehicle holds 5 quarts and you drive 5,000 miles between oil changes, how much oil will be in your car at your next oil change if it burns one quart every 2000 miles? Answer: 2.5 quarts. What if you drive a GM pick-up up the Rockies? Most pick-ups hold six quarts but at the rate described in the TSB, you would be three quarts low at 1500 miles.

Our wish for you is to become a fervent zealot about changing your oil faithfully with the right type, the right grade, the correct weight, the right frequency and to check your capacity every other time you fill up for gas.

Sources

Oil Grades

http://www.gf-5.com/timeline/

http://www.gf-5.com/the_story/performance/

Oil Weight

http://auto.howstuffworks.com/fuel-efficiency/fuel-consumption/question1641.htm

http://www.motoroilmatters.org/About-Motor-Oil/Learn-About-Standards

Environmental Concerns and BMW

http://www.thecarconnection.com/news/1070781_changing-your-oil-too-often-you-might-be-surprised