The use of oils formulated for diesel cars cannot be used in gasoline cars. In the past, diesel engine oils were used because of their higher viscosity, which was a bad reason. Engine oils turn black due to their cleaning power when used.
The American Petroleum Institute shares the quality of engine oils in two categories:
- رEngine motors for gasoline vehicles with the first letter of service station (S) that display the quality level in English letters A (lowest quality level) to N (highest quality level)
- Engine oil for diesel cars with the letter “Commercial” (C), which shows the quality level in English letters A (lowest quality level) to J (highest quality level).