By: Sue Christophersen
We pump our own gas, we check the oil level. Many women are also shopping the automotive department at the local parts store for motor oil. In fact, in households that fix their own cars, 1/3 of the do-it-yourselfers (DIYs) are women, according to the Automotive Aftermarket Industry Association.
As with most DIY projects, materials are important. Like shopping for food and medicine, it helps to know what’s on the label. The most important advice when looking for engine oil is to follow your vehicle manufacturer’s recommendation. This is found in the owner’s manual and sometimes on a sticker under the hood.
The Society of Automotive Engineers (SAE) and the American Petroleum Institute (API) have established several classifications that define the characteristics of engine oil.
This label is identifies engine oils recommended for a specific application, such as gasoline engines.. Oil may be licensed to display the Starburst only if the oil satisfies the most current requirements of the International Lubricant Standardization and Approval Committee (ILSAC) minimum performance standard for this application. Many vehicle manufacturers recommend oils that carry this API Certification Mark.
The API classification is a two-letter code that defines the oil performance characteristics under different engine speeds, loads, and temperature. The letter “S” is for gasoline powered engines and the letter “C” (for Commercial) is for diesel powered engines. The second letter of the code indicates the level of protection the oil provides, The letter “A” was first used for vehicles back in 1930 and the codes have moved up the alphabet as oils have changed. The most current API classification is the letter “N” Oils marked with SA through SH are considered obsolete and if it is SE or older, it could possible harm your engine.
The SAE classification, in the center of the donut shaped logo, indicates the oil viscosity; the higher the number, the thicker the oil. Thick oil has a high resistance to flow, or high viscosity. Oil classified with a “W,” like 5W or 10W for example, indicates the viscosity rating applies at subfreezing temperatures and is generally used for winter conditions. If there is a number shown without a “W”, this means that the viscosity rating applies at 212°F.
The problem with single grade oil is that the W oils tend to thin out too much in warmer weather and the non-W numbers tend to thicken too much in colder weather. Single grade oils are generally meant for one temperature only and require seasonal oil changes. That is why most vehicles today call for multi-grade oil like 5W-30 or 10W-30. These oils have suitable flow properties at both ends of the temperature spectrum, no matter what the season. Again, always follow your vehicle manufacturer’s recommendation to be sure you are using the right oil.
Fuel Economy Rating
The third part of the label classification is the “Energy Conservation” or “Resource Conserving” term. Oils with this classification are designed to reduce internal engine friction and may improve fuel economy.
There are many synthetic oils on the market today and a lot of advertising to promote them. They tend to wear longer and may perform better in extreme conditions. They are also slightly more expensive, and if this is what the vehicle manufacturer recommends, then this is what should be used. Synthetic oils tends to be thin and very free flowing so it is not recommended to use in older, high mileage engines. These engines may have more mechanical wear, allowing for more internal oil leakage resulting in higher oil consumption. Keep in mind also that although the oil may be advertised as high performance for extreme conditions, it gets dirty. The price of synthetic oil is considerably higher, making an oil change much more expensive.
So next time you decide to do your own oil change and go shopping for oil, you will have a better idea what to look for. Follow your vehicle manufacturer’s recommendations and make sure you are buying the best rated oil product for your ride. Change your oil according to the recommended maintenance schedule and always replace the oil filter when changing oil.