Cat 3116 oil change

[Roger3116]

Let me first say how much I enjoy this form and how amazed I am at the knowledge of its members. For my first question. I would like your opinion on how long I can go between oil changes.. I have a 1996 Topkick with 180,000 miles and a 215HP cat 3116 engine. I drive about 3000 mi per month and use Shell Rotella 15W40. The recomened interval is 6000 mi, which seems very short for a motor that has a capacity of 20 liters of oil. I have done 2 oil analysis-- 1 at 6000 mi. and 1 at 8000mi. I have posted the results below and would like some advice on the results and the oil change interval.

 

[userfriendly]

Roger;
Does the engine use any oil in that 8,000 mile interval?
We have those Top Kicks on the railway.
I would be surprised if they have the oil changed once a year.
The Diesel fuel in Canada is all .5% or lower sulphur, so its not particulary hard on the oil's TBN retention level.
You may be able to move up to Shell's new Rimula CI-4 and change the filter at 8,000 miles and the oil at 16,000 miles with UOA support.

 

[Roger3116]

The truck used 2 litres in 8000mi. Here are the analysis at 8000 and 6000 miles. 8000--Fe18 Cr3 Mo1 Al8 Cu2 Pb1 Sn0 Si3 Na33 Zn1075 K3 Ni0 Ag0 soot90 sulf10 oxid57 nitr24 6000--Fe15 Cr3 Mo1 Al13 Cu3 Pb1 Sn0 Si3 Na19 Zn1032 K3 Ni0 Ag0 soot 80 sulf8 oxid57 nitr26 Any help would be much appreciated. Roger

 

[Steve S]

I don't think that you would notice much difference in any of the proper oils in your truck unless very cold temperatures are involved.

 

[Roger3116]

I am asking how long the oil change interval should be.

 

[MolaKule]

I think Userfriendly gave some good advice. Base the changes on some UOA trending.

The analysis results looked good for a diesel.