Difference between various types car engine oil grades

Car engine oil has different components that give it unique characteristics. So, these unique characteristics make the oil ideal for serving the different types of engines. This is highly affected by the engine CC size because high performance engines need highly performing oil.

You may be wondering how does oil performance take place? Well, it’s very easy, there are a bunch of things that car engine oil does for the engine.

Roles of car engine oil.

  • Cleaning.

Car engine oil is very effective in cleaning deposits within the engine. It’s important for the engine to stay clear of any deposits because they reduce performance and  fuel efficiency. That accumulation of these deposits is preventable depending on the oil’s resistance to sludge. That is, the oil keeps the particles afloat until the oil goes through the oil filter.  Engine oil removes particles through filtration which happens within the oil filter. Changing the oil is a very important part of car maintenance.

  • Lubrication.

It serves this role to make the engine parts to easily move by creating a film on them. This film makes the parts slippery hence reducing the amount of friction. This in turn makes performance reach its peak especially when the engine is operating at normal power. During engine start-up it is very possible to incur friction because the oil sinks to the oil sump. Do not apply intense acceleration as soon as the engine starts. Because the oil hasn’t circulated the engine block and immediate acceleration puts the engine parts at risk.

This function is served by the oil’s viscosity index which determines how well and how fast the oil flows through the engine block. Viscosity index is a very important factor to consider when you’re choosing among the different types of oil. If the oil can flow fast enough, it will be very efficient during the cold engine start or during extreme cold. The wrong engine oil could increase the engine’s temperatures and it won’t serve the next purpose we’re going to look at.

  • Cool.

Oil is counted amongst the engine cooling system components. The engine coolant is responsible for the purpose of cooling the upper parts of the engine. It goes through the radiator where the coolant passes over water for cooling purposes. Afterwards, it’s pumped back into the engine to cool it’s parts.

Alternatively, oil cools the following engine parts; crankshaft, camshaft, timings gears, piston, main and connecting rod bearings amongst others. Since the engine becomes heated up from combustion and friction, the oil passes over those surfaces to cool them. Then the hot oil passes to the oil sump where it cools down.

What are car engine oil grades.


Oil grades represents the two main methods with which different types of car engine oils are classified as. These metrics include;

  • Viscosity.
  • Reaction to temperature changes.

Every type of car engine oil possesses different density which affects viscosity while the chemical composition affects the oil’s reaction to extreme temperatures. You will notice an alphanumeric code on all engine oil containers to represent the two major metrics. The alphanumeric code represents the oil’s viscosity at different temperatures. For example 20W-40

  • 20W

This number is followed by a W and it represents the oil’s viscosity reaction to winter temperatures.

The smaller this number is the better it will flow under extreme cold weather or under a cold engine start. For example, 10W-40 flows better than the 20W- 40.

Alternatively, the larger the number is the poorer it flows under cold weather conditions. For example 30W-40 flows slower than the 20W-40.

  • – 40.

This number represents how well the oil flows during normal engine operating temperatures.

In this case, the lower the number, the better the oil flows during normal engine operation temperatures. For example 30W-40 will flow better than the 30W-50 engine oil.

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button