Basic Car Maintenance Tips Engine Oil - Synthetic, Conventional, SAE Numbers and Viscosity
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Basic Car Maintenance Tips Engine Oil - Synthetic, Conventional, SAE Numbers and Viscosity

Engine oil ranges from fully synthetic oil to partially synthetic oil to conventional oil. Learn about the types of oil and how to check and add oil to your car to preserve the life and effective operation of your car.

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 in the engine oil 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. It is recommended that the oil filter be changed when you have your oil changed. Selecting the correct oil filter is important. Different car models require different oil filters and generally are not interchangeable. Your car manual will have oil filter specifications.

Types of Engine Oil

Synthetic engine 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 motor oil. 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 motor oil is cheaper than fully synthetic oil. Conventional engine 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 to add engine oil to your car and you can only find synthetic or conventional it is ok to add it. The major manufactures of synthetic oil, Mobil 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

Get Your Oil Changed - DO IT!

Your owner's manual will tell you how often to change your oil. If there is one simple thing you can do to increase the life of your engine it is changing the oil. A rule of thumb is every 3000 miles or every three to six months. Motor oil gets dirty and carries particles and grit that circulate through your engine. The oil filter takes care of the bigger particles but as the oil gets older it gets dirtier and starts to break down. See your car manual for the recommendation regarding the mileage at which you should change your engine oil and oil filter. 

Oil Warning Light

This is that little red light that lights up on your dashboard and usually has a little picture of an oil can or the word oil on it. Some people assume that the light is just malfunctioning and they keep tapping it to try to make it go off and they will insist that it is broken because the oil dip stick reads full.  Just because your dip stick reads full doesn’t mean your engine is getting oil. There can be any number of things wrong that prevent oil from getting to your engine. If your oil light goes on find a safe place to pull off the road and shut down your car as soon as possible. If your engine starts making a banging noise the situation is urgent.

Checking and Adding Oil

Turn off your car and let it cool a bit before checking the oil. The oil dipstick handle will often, but not always, be yellow. If there is another dipstick toward the rear of the engine with a larger tube it is likely the transmission fluid dipstick. Pull the oil dipstick out of the tube and wipe it off. Look at the end and familiarize yourself with the markings that say low and full. Push the dipstick back into the tube all the way until it is seated properly at the top then pull it out again and examine the end to read the level. If it is low you will add the oil by removing the cap that says oil or has a picture of an oil can. Do not over fill and try not to spill oil on the engine.   

 Basic Car Maintenance Tips: Antifreeze and Coolant

Basic Car Maintenance Tips: Automatic Transmission Fluid (ATF)

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Comments (10)

I never changed the oil on my first car. I was half way across Nova Scotia in the middle of nowhere when the engine blew! Wish I would have read this article beforehand.

Yes, I know the feeling :( . It is a sick sinking feeling like boy this is gonna cost me money and how the heck am I gonna get a tow truck to come out here.

Thanks! I always enjoy reading about cars. I am more of a computer expert than car expert and need to read a lot about cars.

I'm useless when it comes to cars; just as well I don't drive. Great write.

Well, I don't claim to be an expert but I think I have the basics figured out from a few bad experiences and the loving nagging of my husband! Since we always buy used cars it is even more critical to keep up with the regular car maintenance. Thanks for the votes and comments.

You're so right. Oil is the lifeblood of your engine. If it gets black, its time to change. Synthetic motor oil, although a little bit more expensive than other oil types, is best.

Nice job here too Judith. Just one thing to add that you over looked. Unlike when checking ATF levels, the engine needs to be shut down before checking motor oil level. Shut the engine off and let the car set for a couple of minutes giving all the oil a chance to drain down into the oil pan before checking its level.

"Idiot light" is appropriately named. If driving that this thing lights up, it is almost too late. Assuming it was not a catastrophic leak like blown oil line or sucked-gasket, the 'low level' has been a longer-term problem. Here is where an OIL PRESSURE GAUGE is really useful. Although a bit difficult for the backyard mechanic to install and really, I have never seen any there were attractive when installed on your dash, a mechanic can do the work a lot quicker. It you have an oil-pressure gauge, keep an eye on it. These are far more useful than the 'dummy lights' which only come on when ultra-critical.

Hi Stickman, I come from the era of custom cars and hot rods. I'm a firm believer in gauges.

Thanks for the heads up on that tip Jerry. Yes car off and sitting when checking oil. That is an important point!