[sbbtmatt]

I am sure this is a repost but there are so so many posts i cannot find exactly what I am looking for. My 6.7 is up to about 110k and now that the warrenty is done I was thinking of maintaining the truck my self. Is the oil the dealer uses anything special? I know they use that low ash stuff? Should I start using the amsoil? Should I put synthetics in it (I have synthetics in the trans, dif, ect) are they worth it in the motors, if so which one? I also have an 06 5.9 with about the same miles would that be the same oil?

 

[Thundercraft]

The 5.9 is a good candidate as it has no DPF or extra injection cycle during the exhaust stroke - so fuel dilution shouldn't be an issue.
Does it need it? That is a question for you to answer. As you already use synthetics, you will be pretty familiar with the advantages that they can offer.

the 6.7 is a little more debatable - especially if the DPF hasn't been taken care of.
The oil still offers better protection, but you need regular oil analysis to verify that fuel dilution isn't an issue.

Regardless of what type or brand of oil you plan to use, both engines would benefit from an oil by-pass filter system.

 

[TRIMMELL]

Just run regular Rotella 15w 40 that's CJ-4 approved I don't think any of the 15w 40 isn't CJ-4 approved now. You are right it is low ash oil but all our local dealer uses in the diesels is Rotella. That's what most everyone I know uses. Some guys use Amsoil and say it helps with mileage and such but I haven't used it.

 

[48kenworth]

I run regular old rotella and change it every 5k I've never had a problem not in either of my 92'sboth had over 300k,my 93had over 600k,95 300k,99 200k,01 160k,06 5k I didnt like that one ,07 5.9 55k still got it,or my07 6.7 100k still got it. and all of them were running good when I got rid of them.I swear by rotella 15-40

 

[hector]

Amsoil offers a 15w-40 in CJ-4 & 15w-40 CI rated oil. If you are going to use Amsoil,,,Be sure to order the correct rated oil for your 6.7

 

[seanth468]

If you are going to keep the emission stuff, just use dino oil. The egr keeps the oil so dirty that it would be a waste of money to use synthetics.