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Engine Oil

Engine oil is one of the most vital fluids your vehicle needs to operate. It works as a lubricant for the engine and as a means of cooling and cleaning internal engine parts. Running your engine when it is low on oil can result in serious engine damage.

Checking Engine Oil

The best time to check your engine oil is when your vehicle has not been running for a while. If you have been driving, wait at least an hour before checking your oil to give the engine time to cool down and the oil to drain back into the oil pan. Cool oil stays on the dipstick better making it easier to measure the level.

  • The vehicle’s engine must be off.
  • Make sure the vehicle is on level ground.
  • After opening the hood, find the engine oil dipstick and remove it.
  • Wipe off the end of the dipstick with a rag, and notice the markings located near the end of the dipstick. You will usually see a mark for “Full” and another mark for “Add.”
  • Insert the dipstick back into the tube, remove it immediately, and read the level.
  • If the dipstick indicates the level is at or below the “Add” mark, then add oil.
  • Be sure to add only enough oil to reach the “Full” mark. Do not overfill.

When driving under normal conditions, AAA recommends consumers change their oil between 5,000 and 7,500 miles.

What Should My Oil Look Like?

  • New engine oil will generally have a light gold to brown tint and should be nearly transparent.
  • Synthetic oil is normally darker in color, sometimes almost black.
  • If the oil appears milky or thick, or if it is very thin and has a strong fuel odor, there may be a mechanical problem with the engine. If this is the case, have the vehicle checked by a qualified technician.

Engine Oil Terms and Ratings

In 1993, the starburst symbol was introduced to help consumers identify engine oil that is suitable for use in gasoline engines. This symbol, along with the American Petroleum Institute (API) and the Society of Automotive Engineers (SAE) ratings, will help you identify the correct motor oil that your manufacturer recommends for your specific vehicle.

API Classification

This two-letter classification signifies the type of engine (gas or diesel) and the service class. The first letter will be either an S (signifying a gasoline engine) or a C (signifying a diesel engine). The second letter is the service class designator, which has been sequentially assigned since the service classification system started. The letters range from “A” through “J,” with J signifying the most recent improvements in the quality of the motor oil. For example, “SJ” motor oil is suitable for use in today’s gasoline engines, while “SA” motor oil is considered outdated and will not meet the engine oil requirements for modern vehicles.

AAA recommends that motorists use the highest designated oil in their vehicles.

SAE Viscosity Grades

Viscosity grade ratings indicate the oil’s resistance to flow, or “how thick or thin the oil is.” SAE (Society of Automotive Engineers) utilizes a numbering system to grade engine oil. An example of single grade oil is SAE 30, while an example of multi-viscosity grade oil is SAE 10W-30. The “W” indicates that the oil’s minimum viscosity grade was determined at 0 degrees Fahrenheit, assuring that this oil has been tested and rated for use in cold climates.

Synthetic Oils and Oil Additives

Synthetic engine oils possess performance characteristics that are more desirable than conventional engine oil. However, synthetics should still be changed at the same intervals as conventional oils. Synthetic oils clean better than conventional oils because of their ability to hold more detergents. However, the high cost of synthetic oils makes the benefits far less appealing. If cost is not a concern and you desire protection beyond normal driving conditions, synthetic oils may be for you. For the average driver, the money you save may pay for your next oil change or two.

AAA recommends that you don’t spend money on aftermarket oil additives that can diminish oil protection. Engine oil comes with additives already blended into the formula to enhance the oil’s performance and to help meet the demands required by today’s engines. Aftermarket additives often contain the same additives that the oil manufacturers have already formulated into their oil. There is no research that substantiates adding these “cure-all additives” will provide any greater protection. In fact, by adding some of these products you may actually be detracting from the protection that is already built into the oil.