I changed over to amsoil 15W30 at 30K. After doing a bunch of reading to see what people were recommending, most people say that it takes a diesel abotu 25k or so to break-in where a gas will break in somewhere around 7-10k.

As far as oil changes, with the bypass system, I have gone 27,000 without a change and the analysis was still good. That is when I was doing some pulling of a 23ft trailer loaded with an unknown weight. Usually had about 12k or better total load. The 23ft was a car hauler used for other purposes. I did notice a slight drop in engine op temp, followed by an increase in mpg by 1-2. Right now, I have over 30k on the oil and will be sending in a sample in the next week or so. (Need to find my kit so that I can take the sample and mail it.)

I have also changed the transmission over to the full synthetic along with both diff and the t-case. I did put the same gear lube in the t-case instead of the stuff that they recommend on the electric shift.

Other than an o-ring leak on the filter adapter to the dual filter bypass system, it has been a great investment. change 1 filter at 10k and 2 filters at 20k (total) just topping the system off during the service and it is doing fine. I suspect that I will get 40-50k out of a single oil change. Especially with the price of the stuff. It cost about $35 for a single filter change and $55 for a 2 filter change.

 

What Brand is the bypass system that sounds like a lot for the filters.

 

I've done the extended intervals. In my opinion they are not worth it. It's a little piece of mind to know your vehicle is well lubricated every 3-7k miles. All depends on how hard she is driving.

 

Running the AMSOIL bypass with the EAO filters. I usually buy the filters 2 or 4 at a time along with the oil by the gallon. The price listed is for the filter and the oil to top off the system.

 

Ok right on I was going to say you must be buying the filters at retail. How many miles you have on the oil now?

 

just over 30K. Waiting on an analysis to see what they recommend. Think that there may be something wrong with the mail. It's been 2 weeks since I sent the sample in and it only needs to go across town.....

 

Two weeks should be the limit. I think my last one was 10 days. Do you know if you designated by mail or email?
Here again, I'm assuming you used Oil Analyzers??
You might try going here: HORIZON LOGIN
See if you can pull up your results?

 

im going to use two wix 51697 oil filters and valvoline true blue full synthetic 15w-40 oil, how many miles do you thik i could go on a oil change

 

No matter the set up, I always recommend checking it at 7500 miles or so to see how the oil and the engine is performing. You never know, you might uncover something wrong in the engine...hope not. This gives you a baseline and you can kind of go from there. If that came back lookin good, I'd stretch it farther the next time.
Assuming nothing's wrong in the engine, that setup should get you at leat 10k.
Just a guess

 

Amsoil was all i ran in my 5.9.....i loved it....everthing was always good...hadnt started it in the 6.7 yet tho, prob start next oil change