I've got 11,000 on some Warren 5W-30 Semi-Syn, and it still "looks" good... (I change a lot of oil in "abused" vehicles - this stuff 'looks like new' compared to some stuff I drain!)
With Texas heat getting hotter and me doing more and more trailer towing, I'm thinking it's time to change the oil.
I have read some of DNewton3's posts, and he backs his words up with science. For example:
Originally Posted By: dnewton3
Additionally, Ford/Conoco proved this as well. Wear rates DROP as the OCI lengthens.
Check out SAE 2007-01-4133; buy it and read it! Ford tested wear at 0 miles, 3k miles, 5k miles, 7.5k miles, 10k miles and even 15k miles; the wear rates were highest upon the OCI and least after 15k miles!
Generally, there is a parabolic curve that is associated with wear rates. The are slightly higher initially, drop down to nearly nothing, and then escalate again after the oil is compromised past its point to deal with contamination.
The "uptick" in wear is due to the tribochemical barrier being removed by the "fresh" detergent package upon installation. Yes - believe it or not, too much of a good thing is a bad thing. Now, DO NOT read too much into this; I'm not saying it will kill any engine. But what I am explaining, and what is abundantly clear in UOA data as well as supported directly with the SAE article, is that the wear is HIGHER upon the initial OCI, because the cleaning additives actually remove the boundary layer that protects the metal parts. Don't believe me? Read the whole article. And review my "normalcy" article as well; there is CLEAR data that shows the wear rates drop the further out you get from an OCI event.
I stand by what I state; it's true despite what rhetoric may contradict it.
Please provide a link to your referenced article; I'd like to read it.
For reference of my claims:
http://papers.sae.org/2007-01-4133/
and my article:
http://www.bobistheoilguy.com/used-oil-analysis-how-to-decide-what-is-normal/
So, I'm thinking of changing the oil to reduce varnish and possible deposit buildup in the engine (not worried about wear too much at all)
My Question:
Should I leave a little used oil in?
1 quart?
2 quarts? (sump & filter holds 6)
It would add "new add pack stuff",
and some new detergents, etc. ...
...but would leaving a little "old" oil help with the "tribochemical barrier" not getting removed?
With Texas heat getting hotter and me doing more and more trailer towing, I'm thinking it's time to change the oil.
I have read some of DNewton3's posts, and he backs his words up with science. For example:
Originally Posted By: dnewton3
Additionally, Ford/Conoco proved this as well. Wear rates DROP as the OCI lengthens.
Check out SAE 2007-01-4133; buy it and read it! Ford tested wear at 0 miles, 3k miles, 5k miles, 7.5k miles, 10k miles and even 15k miles; the wear rates were highest upon the OCI and least after 15k miles!
Generally, there is a parabolic curve that is associated with wear rates. The are slightly higher initially, drop down to nearly nothing, and then escalate again after the oil is compromised past its point to deal with contamination.
The "uptick" in wear is due to the tribochemical barrier being removed by the "fresh" detergent package upon installation. Yes - believe it or not, too much of a good thing is a bad thing. Now, DO NOT read too much into this; I'm not saying it will kill any engine. But what I am explaining, and what is abundantly clear in UOA data as well as supported directly with the SAE article, is that the wear is HIGHER upon the initial OCI, because the cleaning additives actually remove the boundary layer that protects the metal parts. Don't believe me? Read the whole article. And review my "normalcy" article as well; there is CLEAR data that shows the wear rates drop the further out you get from an OCI event.
I stand by what I state; it's true despite what rhetoric may contradict it.
Please provide a link to your referenced article; I'd like to read it.
For reference of my claims:
http://papers.sae.org/2007-01-4133/
and my article:
http://www.bobistheoilguy.com/used-oil-analysis-how-to-decide-what-is-normal/
So, I'm thinking of changing the oil to reduce varnish and possible deposit buildup in the engine (not worried about wear too much at all)
My Question:
Should I leave a little used oil in?
1 quart?
2 quarts? (sump & filter holds 6)
It would add "new add pack stuff",
and some new detergents, etc. ...
...but would leaving a little "old" oil help with the "tribochemical barrier" not getting removed?