View Poll Results: Oil Change Interval
Voters: 83. You may not vote on this poll
Oil Change Interval
Registered User
Joined: Sep 2003
Posts: 202
Likes: 0
From: St. Louis
Wow, there are a lot of people waisting some perfectly good oil out there. Why? If some of you did a little research, you would come to find that synthetic oil maintains its lubricating properties for quite a long time. Around 15k miles is when you should start worrying about your synthetic oil, but you should have changed your oil filter a couple times by then.
Read This
Read This
Registered User
Joined: Aug 2003
Posts: 3,660
Likes: 2
From: Midlothian
[QUOTE]Originally posted by Destiny2002
From their graph, it looks like the oil is no longer "like new" at 4,000 miles.
I think most owners want to have "like new" oil in their crankcase.
Why would you want to change the oil filter more often and leave the old oil in?
From their graph, it looks like the oil is no longer "like new" at 4,000 miles.
I think most owners want to have "like new" oil in their crankcase.
Why would you want to change the oil filter more often and leave the old oil in?
Registered User
Joined: Aug 2003
Posts: 3,660
Likes: 2
From: Midlothian
There is no doubt that a momentary bypass has relatively clean oil as you say - I cannot predict when the filter will be so dirty that it is in bypass all the time, nor can anyone else - it varies from car to car, driver to driver - that is the point of changing the filter midway through the oil change interval. It ensures that the bypass will not be partially or completely open. It also ensures that a fraction of the oil fill is replenished with fresh oil/additives, and another fraction of used oil removed.
Regarding UOA's not showing copntamination: Contamination should be reflected in the TBN, both in terms of oxidation and acidification. Glycol would show up, as should silicon, etc.
I am not convinced that tiny particles represent a significant wear threat - they are kept in suspension by the oil, and it is practically impossible for them to get three abreast, which would cause some scraping of the bore or cam lobes or bearings. I suggest that if they are significantly smaller than the hydrodynamic clearances that they are only a real danger in the rare occurrence they get next to each other.
The Grand Canyon was formed by water erosion, in part because the water did not keep the small rock debris from carving away at the rock. Suspension agents in the oil are far more successful.
Regarding UOA's not showing copntamination: Contamination should be reflected in the TBN, both in terms of oxidation and acidification. Glycol would show up, as should silicon, etc.
I am not convinced that tiny particles represent a significant wear threat - they are kept in suspension by the oil, and it is practically impossible for them to get three abreast, which would cause some scraping of the bore or cam lobes or bearings. I suggest that if they are significantly smaller than the hydrodynamic clearances that they are only a real danger in the rare occurrence they get next to each other.
The Grand Canyon was formed by water erosion, in part because the water did not keep the small rock debris from carving away at the rock. Suspension agents in the oil are far more successful.
