Wear #'s

[dropitby]

This post is something I wanted to ask and found no clear answer. Let's say you buy a new car and they put in Castrol 5/30. Nissan does not recommend Synthetic oil at all according to the owners manuel.So your suppose to run the oil & filter for 7500 miles.Do the wear #'s start to fall at some point lets say at 15000 miles.Is this the best time to start using Synthetic oil to extend your OCI.Do we as Blackstone told me dump it at 3000 miles to clean out the wear metals sooner.There you have it two points of view but the real question everyone wants to know before they leap to more expensive oil and want to go to longer OCI is do you stay with the factory recommended oil till the wear metals stabilize which is what I am getting from Blackstone.Or do you change early not knowing if the engine is fully broken in. Thanks in advance for your response.

[ September 18, 2004, 10:26 AM: Message edited by: dropitby ]

 

[buster]

I just switched over at 1,200 miles to synthetic. I broke my truck in pretty hard. It suggests that you do this in the manual. Both Amsoil/Mobil will tell you that changing over at any time is fine. Cars today don't need elaborate break ins. Wear metals will be higher initially. The reason it is good to not switch over to a synthetic so soon is that you should do frequent oil changes initially to flush out the wear metals and your going to be wasting $$ on good synthetic oil by doing this.

 

[Al]

I think both posters brought up good points. I can't really disagree with any of it. But my gut feeling is still that it is a good idea to get the origional oil out of there at say 1000 miles. But I must say there is abslutely no proof that this does any good. I have rpplaced the origional oil with synthetic at well under 1000 miles in several vehicles. I replaced at 30 miles in my Nissan Sentra.

I like the idea of an oil sample within the first 5000 miles to get a baseline and hopefully the wear numbers will come down-which they almost always do.

I would be surprised if your Nissan stated specifically that they do not recommend using synthetic. I have never seen that except for the Rotary Mazda. My Nissan says not to mix synthetic and synthetic(which is bogus

)

 

[Roger]

As I recall, you are correct Al. I test drove a Quest earlier this summer and the owners manual said it recommends mineral based oils. What caught my eye was the absence of any reference to synthetic oils, as previous Nissan manuals specifically do say is okay to use. The manual was silent on synthetics.

dropitby , the only person I've ever seen produce a little evidence (as opposed to pure opinion) to support the idea of holding off using synthetic oil is bill99gxe at the maxima owners site. Based on the uoa's he's collected in that site's spreadsheet, he feels owners who delay using synthetic oil for awhile (in only those specific Nissan engines) tend to have slightly better wear later on than those who switch right away. Whether that is applicable to other makes and engines is hard to say.

The only thing I've noticed reading reports in the uoa section on this site is that new engine breakin varies widely, some engines take as long as 15-20K miles. Others in as little as 3-5K miles.

 

[dropitby]

Al I thought I would write what is written on Section 9-5. Nissan recommends mineral based oils.These oils must however,meet the API quality and SAE viscosity ratings specified for your vehicle. ADDITIVES Nissan does not recommend the use of oil additives.The use of an oil additive is not necessary when the proper oil type is used and maintenance intervals are followed. Oil which may contain foreign matter or has been previously used should not be used. (Does this mean GC HA HA.)

 

[buster]

I'd guess that Nissan doesn't want people using synthetics bc they most likely want them comming back to them for oil changes. Synthetics can be used in any engine at any time for 99% of all engines. Long break ins are a thing of the past.

 

[Roger]

Nissan's choice of words does make you wonder why they said mineral based, instead of something more generic like "quality" or simply API SL, SM, etc.

 

[Al]

Considering that many-if not all, of the new GF-4 oil will use signifficand synthetic base (Group III or IV) I wonder if they will change their manuals.

I would tend to agree with Buster in that synthetics shold pose no problem at all. But Roger-I can't dispute your information.

 

[Spector]

Blackstone, like anyone else, cannot prove that high wear metals in a sample, if left there for continued use, contribute to more wear. They feel it does but canot prove it! Si, yes, no doubt over a cut off point will contribute to more wear. However, the wear "metals" measured in a UOA are too small IMO to cause further wear (maybe at some point the build up is enought to do so), but no one, no one, can tell you what that magic number is. Is it 50 ppm of iron or lead or 500 or 1000. In one of my enignes the ave lead is 26 ppm per 7500 miles over 12 years (most would say I had a major problem) and the engine still runs fine.

Interpreting UOA is an art as Terry knows but very little facts abound as to what each number means for each engine etc. IMO this board places way to much emphasis on wear metal counts being high, the concern should be are they consistent over multiple UOA under similar conditions and mileage.
All that changing your oil does at 1000 miles is lower the wear numbers, it does nothing to address the problem if there is on, it just makes you feel good!

 

[dropitby]

Well I thank you for your answers but that takes me to the next question.If Blackstone thinks I should drain the oil sooner because the wear metal are high then as you stated there is no proof that leaving the oil in will hurt anything why then do we change oil if it were not for high levels indicating the oil may have lost some of its ability to do one of its jobs.The Nissan manual tells us its ok to leave oil in for 7500 miles but we know better that that so we change it for shorter intervals to get rid of the preceived higher level of wear metals thus extending breakin.I for one have read many oil reports that tell people why did you leave it in so long the report looked terrible yet the bottom line is something may have been done added to or something to change what normally would be a good report into something else.You have to know as AL pointed out in another thread of a engine useing Penzoil 5w30 at 600 mile a 1000 miles later sheared down to a 20 wt. Of course there is nothing wrong with the oil in a normal engine but had they used M1 the out come may have been different.I will continue to think the engine will breakin faster on mineral because it breaks down sooner. So after its broke in your report with your Penzoil will look much different.Thanks again.