Timely Oil Changes

Try JG. THe advanced oil analisis for $26.00 gives you the TBN.
http://www.jglubricantservices.com/online_store.html
Bill

Here is a link to Blackstone labs pricing. A standard test is $25 and TBN is an additional $10

Blackstone Labs Tests and Pricing

I have just read this whole thread and find a lot of information on oil testing that is not correct. I ran an oil test lab when I was in the Air Force. Doing only one test will only give you a snap shot of what the conditions are right now. The best way is to do more than one sample say every 5000 miles. You have to have several samples that will establish a trend. I am using JG Lubricant services to do my analysis. On my report it does give a report on additives. They are mostly different metals. The main ones are Magnesium, Calcium, Barium, and Phosphorous.
The lab can flag the additives that are getting low.
When I got my RV I did an oil change because I had no records. I went on a 1200 mile trip before I sent in the first sample. This October after completing an 8439 mile trip I sent in a second sample. My oil still tested good. My wear metals Iron was 29 now 58 parts per million. That is an increase of 30 ppm. I think that is well within the normal wear pattern. The other wear metals tested Chromium went from 1-2 ppm. Aluminum 3-5 ppm Copper 0-2 ppm. Silver0-1 ppm the rest were 0.
You will also get a report on contamination.
I am running Mobil 1 Turbo diesel truck. 5-40. For my engine Cummins the recommended oil change is 15,000 miles or yearly. I could go longer but will change my oil before heading out on a long trip this spring.
You can also sample your transmission I have done a fluid and filter change on my Allison 300MH and Allison says I can go 250,000 before change but if it is sampled and found good you can extend the mileage/time.
The best advise to the gas engine owners are to change at the recommended interval. I do recommend the use of a synthetic oil. Mobil one is my go to oil. I use the same oil in the genarater as the main engine.

An oil analysis is $30-35 and will answer the question if you are changing your oil too much or not enough. If you request a TBN analysis (extra $) it will give you an indication of how much is left.

OK, so that seems useful. (learned something) Knowing that oil is designed for all the additive to be used at the same rate, one indication will give you indication of everything else.

On an oil analysis, the TBN number is directly related to the amount if additives in the oil.
Blackstone knows the TBN for any oil you want to use, and you can also look this number up on any number of sites.

By comparing the TBN numbers, you can tell how much of the additive pack remains.

Daveinet wrote:

jhilley wrote:
...It doesn't show the additives left, but it shows what is controlled by additives and whether or not they were with in normal ranges. As far as wear, how would you predict in advance? This tells you before your engine is ruined.

That is kind of why I have a problem with it. It shows that what you did was ok, and it would tell you if it was not OK, but you really don't know how much you have left. It would seem that you could send in a sample every 500 miles and then graph the results. When you see the cumulative wear rate start to increase, then you know at what point you would need to change the oil. While you could do that to create a base line, there are outside factors that can affect the the wear rate. So if you are going to push the limit, you don't know where the edge is.

You could certainly do that, but it would be very expensive. Testing every 5,000 to 7,500 miles would show up any anomaly in wear. Unless there is a problem nothing will show up. If there is a certain element showing up in higher amounts than average, it can pin point what is failing by composition. For extended use of oil, it is a verification that the type and weight of oil and conditions of use is compatible with that use and mileage.

jhilley wrote:
...It doesn't show the additives left, but it shows what is controlled by additives and whether or not they were with in normal ranges. As far as wear, how would you predict in advance? This tells you before your engine is ruined.

That is kind of why I have a problem with it. It shows that what you did was ok, and it would tell you if it was not OK, but you really don't know how much you have left. It would seem that you could send in a sample every 500 miles and then graph the results. When you see the cumulative wear rate start to increase, then you know at what point you would need to change the oil. While you could do that to create a base line, there are outside factors that can affect the the wear rate. So if you are going to push the limit, you don't know where the edge is.

As long as my engine is under warranty, I'll do what Cummins says...change at 20k or one year which ever comes first. Once out of warranty, I might go the oil test route and extend change intervals if the test comes out okay.

Any reviews for Newmar Ventana or Forest River Berkshire?