Engine Oil Facts and Information

There are a variety of engine oil choices available on the market. Motor oil ranges from fully synthetic oil to partially synthetic oil to petroleum oil. Choosing a car oil need not be confusing if you arm yourself with a little knowledge.

Purpose of Engine Oil

Purpose of motor oil is to separate moving parts with a thin coating of lubricant thereby reducing engine wear. It also assists in keeping your engine clean by suspending dirt and particles which stay suspended until your next oil change.

Purpose of Oil Filter

The oil filter will filter out some of the particles and contaminates to help keep the oil cleaner as well. It is recommended that oil filters be changed when you have your oil changed.

Types of Engine Oil

Synthetic Oil refers to a lubricant that is synthesized and is not made from crude oil. Synthetic oil is considered a superior choice as it performs better at low temperatures and is more stable at high temperatures and does not break down as easily. It is also cleaner and has fewer impurities and contaminants than conventional oil has. Partially Synthetic Oil is a mixture of synthetic and conventional oil. My research shows that opinion is generally against a partial synthetic and in favor of fully synthetic oil. However, partially synthetic oil is cheaper than fully synthetic oil. Conventional oil is the petroleum oil that has been used in cars from the beginning. It is the oil that comes out of the ground.

Can Oil Types be Mixed and Can I Put Synthetic in My Old Car?

Yes, conventional oil and synthetic oil can be mixed. So if you are out and about and need oil in your car and you can only find synthetic or conventional it is ok to add it. The major manufactures of synthetic oil, Mobile 1, Valvoline, Penzoil all claim that fully synthetic oil can safely and effectively be used in old cars and that you can switch to synthetic even though you have always used conventional oil with no adverse effects.

What do the Numbers Mean? SAE Designation

The SAE is the Society of Automotive Engineers and they classify oil by it’s viscosity. Viscosity changes with temperature variation so you will often see what is called a multi-grade oil. 10W-30 is a common designation. The ‘W’ stands for Winter. So in the winter or cold weather your oil will have a viscosity rating of 10 and in the hot months it will have a rating of 30. If you live in a particularly cold climate you may want to choose a 5W designated oil that will operate well at even colder temperatures.

The designations do not indicate the outdoor temperatures rather it is an expression of the flow rate of the oil measured in a controlled environment. It is a measurement achieved using a viscometer. However that being said, it is significant to know that a 5W operates better at very cold temperatures than a 10W.

Additives in Motor Oil

Much of the car oil on the market today have additives. These are components that enhance the performance of the oil and give extra protection to your car’s engine.

• Detergents help prevent deposits on high temperature parts
• Anti-wear agents deposit a layer of film on moving parts
• Rust inhibitors do just that – they help prevent rust from forming on your engine parts

Car Manuals

Read your car manual section on oil to determine what is best for your car if you have a newer model car. Many of the older car’s manuals (if you can even get one) were written before synthetic oils came on the market.