30-05-16, 11:38 AM
You can tell if oil is awful immediately, or after a short time.
You can tell if it is below average only after 30-50 k miles. Increased engine wear compared to wear with a good oil.
An oil test after 6k miles of the new oil you're trying out can help determine the quality.
The point is: people buying a different oil brand, pouring it at the oil change and saying "it's good" gives one only confirmation that the oil isn't awfully bad to cause problems immediately - clutch, gear changing, engine noise etc. But by no means can you be certain the oil is really good by "testing" it like that.
You can tell if it is below average only after 30-50 k miles. Increased engine wear compared to wear with a good oil.
An oil test after 6k miles of the new oil you're trying out can help determine the quality.
The point is: people buying a different oil brand, pouring it at the oil change and saying "it's good" gives one only confirmation that the oil isn't awfully bad to cause problems immediately - clutch, gear changing, engine noise etc. But by no means can you be certain the oil is really good by "testing" it like that.
Most things done in a hurry need to be done again - patiently.