COPYRIGHT WARNING:
All pictures and texts in this web page are the property of nomaallim.com. Any use of any part of those contents without the written consent of nomaallim.com shall be subject to legal procedures as per international and local laws in the concerned country. Using the name "nomaallim" or "nomaallim com" or "nomaallim.com" in the text describing the unauthorized copied content shall not constitute an exception and shall be sanctioned in accordance to the effective laws and proceedings.
All pictures and texts in this web page are the property of nomaallim.com. Any use of any part of those contents without the written consent of nomaallim.com shall be subject to legal procedures as per international and local laws in the concerned country. Using the name "nomaallim" or "nomaallim com" or "nomaallim.com" in the text describing the unauthorized copied content shall not constitute an exception and shall be sanctioned in accordance to the effective laws and proceedings.
|
|
|
DISCLAIMER:
Our pictorials are of informative nature and do illustrate works carried out by ourselves at our own premises for our own use and satisfaction.
Readers who envisage to carry out similar works inspired by the below method shall do this at their own risks and liability.
Our pictorials are of informative nature and do illustrate works carried out by ourselves at our own premises for our own use and satisfaction.
Readers who envisage to carry out similar works inspired by the below method shall do this at their own risks and liability.
What are Motor Oil Grades
Engine oil grades describe the viscosity of oil, meaning how thick is the oil and how it maintains such thickness with temperature.
The grades are more than important, as they should match the recommended oil grade given by the automaker for a particular car model end engine model.
The use a motor oil grade that doesn't match the one recommended for your engine can result in many problems:
The grades are more than important, as they should match the recommended oil grade given by the automaker for a particular car model end engine model.
The use a motor oil grade that doesn't match the one recommended for your engine can result in many problems:
- increased oil consumption
- increased emissions and pollution
- sludge building
- accelerated piston rings wear
- catalytic converter and/or particulate filter damage
- turbo damage (if fitted)
- engine damage
Motor Oil Grades Comparison Chart
You will find many motor oil comparison charts recommending oil selection based on ambient temperature or summer / winter.
This is an absolutely obsolete way of selecting motor oils, that was valid up to the early 1990s, when cars had minimal anti-pollution devices, also down-sized and high efficiency engines were not yet massively introduced.
This is an absolutely obsolete way of selecting motor oils, that was valid up to the early 1990s, when cars had minimal anti-pollution devices, also down-sized and high efficiency engines were not yet massively introduced.
|
|
|
|
Instead, we propose a modern indicative comparison oil chart as per the below, noting you should first follow the automaker recommendations:
20W50 |
10W40 |
0W20 0W30 |
5W30 5W40 |
Mineral |
Semi-synthetic |
Synthetic |
Synthetic |
Used on most old cars, even as a replacement to monograde SAE40 oil. Prohibited on modern vehicles from the 1990s onwards. |
Used on a wide range of engines, especially those atmospheric (no turbo), or with indirect injection. Not to be used on turbo direct injection engines as it could result in sludge building. |
To be used on modern cars strictly when recommended by the automaker. Do not attempt to use 0WXX oils if not recommended, as this can damage your engine. They greatly contribute to lower fuel consumption and emissions. |
Used on most modern engines, with or without a turbo and whether equipped with direct or indirect injection. The 5W40 can be used to replace the 5W30 on high mileage engines to reduce oil consumption. There are however other viscosity related parameters to be taken into account (see further below) for high performance engines. |
Why grades are sometimes not enough to select the right oil
Downsized engines equipped with a turbo and a direct injection system, do concentrate a lot of power into a smaller engine block, and therefore do operate under normal conditions with an increased temperature of the metal parts.
This requires oils that can withstand such temperatures without carbonizing, thus the need to further check the flash point and the high shear viscosity characteristics.
This requires oils that can withstand such temperatures without carbonizing, thus the need to further check the flash point and the high shear viscosity characteristics.
Can engine oils of different makes be mixed together?
YES, motor oils of both same grade and similar characteristics can be mixed together, regardless of the make.
If for example, you still have 1.6 liters of oil from a previous oil change, and your sump capacity is of 4.8 liters, you can get the rid of the 1.6 liters from your stock and add 3.2 liters of another oil that has the same grade and same characteristics (flash point, high shear viscosity), when such characteristics are to be matched as explained above.
If for example, you still have 1.6 liters of oil from a previous oil change, and your sump capacity is of 4.8 liters, you can get the rid of the 1.6 liters from your stock and add 3.2 liters of another oil that has the same grade and same characteristics (flash point, high shear viscosity), when such characteristics are to be matched as explained above.
See also our other tips and pictorials on engine oils:
|
|
|