Motor oil specifications and types

Everyone has heard about motor oil specifications (such as 0W-30, 10W-40, 20W-50... etc.) and motor oil types (synthetic oil, conventional oil… etc.). However, few really understand the meaning behind those terms and the suitable motor oil for their vehicle.

Motor oil specifications:

The motor oil specifications identify the viscosity of the oil and follow the universal form “xx W – yy”.

•  The term ‘W’ stands for winter.
•  The ‘xx’ indicates the viscosity of the oil when the engine is starting in cold weather (Around -17 ˚C). A lower viscosity triggers a smoother start-up in cold areas and provides an easier task for the oil pump.
•  The ‘yy’ refers to the viscosity of the oil when the engine is in ideal working temperatures (Around 100 ˚C). A high viscosity in hot conditions results in a thicker oil that is suitable for hot countries and older engines.

Additionally monograde oils exist (such as SAE 30, SAE 40…) but are no longer used in modern automotive engines.

The table below indicates the suitable oil grades for different temperature ranges:

Oil Grades	Temperature ranges ( in ˚C)
0 W - 30	-35 à 35
5 W - 30	-25 à 35
10 W - 30	-20 à 35
10 W - 40	-20 à 40
15 W - 40	-10 à 40
20 W - 50	0 à 50

Motor oil types:

Motor oil types differ in cost, additives that they contain, and usage from one and another. Four general types of oil exist:

• Full synthetic motor oil:
  This type of oil has 0 impurities due to the extra chemical engineered process that has gone through. Therefore, it is the best for people seeking to achieve the engine’s peak performance. Additionally, it contains many additives that protect the engine against oxidation, high and low temperatures…However, it costs up to four times (4x) the price of a conventional oil.

• Conventional oil:
  The most commonly used type of oil. It has less additives and presents less protection than the other types. However, it does its job to lubricate the engine and it is much cheaper than the other types.

• Synthetic blend oil:
  This blended oil is a mix of both conventional and synthetic oil in addition to some additives. It is becoming extremely popular nowadays because of the similarity in aspects and protections to the synthetic oil while costing much less.

• High mileage motor oil:
  As the name shows, it is made for vehicles with high-mileage (more than 75000 Miles), especially modern cars because of the additives it contains which help reduce and protect from leakage, corrosion and oil burn-off. Money wise, it costs almost the same as the synthetic blend oil.

Conclusion:

Therefore, to pick the suitable oil grade and type for your vehicle:

•  If the car is produced for your country/area, check the owner’s manual.

• If your vehicle is imported, seek assistance from a local expert.
• Check the temperature’s range in the upcoming 5-6 months especially if you are in an area that the temperature flactuate significantly.