I bought my first diesel a several months back and I currently change the oil every 5000 miles with regular 15/40.
Are there any advantages switching to synthetic engine oil?
I find the oil goes black soon after an oil change, is that common on the 3rd gens?

 

It helps with cold starts, you would notice a difference where you are. But it's mainly used for extended drain intervals. They claim you may get better mileage by running synthetic but I highly doubt you will ever see a difference.

It's not going to matter what kind of oil you run, as soon as you fire it up it's going to turn black, it's soot. Nothing to worry about there. They do make kit's that claim to remove nearly all of the soot from the oil. I can't say if it works or not. The FS2500 seems to be pretty popular around here, it will also extend the oil life greatly.

 

I run synthetic and did not switch to it until 20k miles. I, ALSO, run the FS-2500 engine oil bypass system. The oil still goes black within the first 100 miles.
I use my truck for towing the rv only - otherwise it sits in the garage. Wil be 3 years old in June and has not hit 30k miles yet. I still do once annual oil change at least until the Cummins 5 year warranty is up. pcm

 

DonM posted some info on some oil tests and his recommendations. I think it was in a thread about wear on the rockers or something like that. Sythetic is good.

 

I just bought my 04.5 4x4 and was told the oil was changed just before I picked it up. The oil is black after driving about 200 miles. Is this normal in the 3rd gen diesels? I have a 95 12 valve and the oil has always stayed relatively clear till about 4000 miles after a change.

 

My fresh, clean oil is black by the time I drive it around the block to verify pressure and check for leaks immediately after the oil change Doesn't take long with the 3rd gen trucks, and there really isn't anything you can do to stop it from happening.

 

thanks, good to know. I thought I bought a truck that was idled alot or didn't have regular service

 

Thanks for the replies.....will try searching for the oil tests posted by DonM.

 

look for an oil rated API CJ-4, it is the newest diesel standard developed in conjunction with Cummins... a synthetic will usually allow you to go longer for your drain / refill cycle... but the basic performance should be about the same..

the older standard is CI-4

http://www.apicj-4.org/

 

Good info................thanks pdogg!

 

Actually i think DonM was saying that he was observing rapid cam wear on trucks that were running CJ-4. If you have an pre 2007 you should run a CI-4 oil. The new CJ-4 is made to work with all the new emissions crap on 2007+. All the new rotella is CJ-4 these days (and not a true synthetic). I like the redline or amsoil CI-4 synthetic...

 

I live in Edmonton, work in the patch. I've Used Amsoil syn. in the past but have switched to Chevron Delo 400 5W-40 Syn (for 6 yrs. now). It is cheaper and cranks over at - 20C no problem and starts. I also change every 8,000 km. Website says oil is for turbo charged engines operating in Extreme cold or high heat (kinda like our climate +30C to -35C).

 

it is also backwards compatible with CI-4... check the spec.. fully compatible with older engines.. If Cummins signed their names to this, I'm pretty sure they tested it... and they did..

 

The new oil is for the newer emission, egr engines.....6.7 cummins etc.

They reduced some of the good stuff in this newer oil that we need, like Zinc and Phosphorus. In some of the extreme cases (higher pressure valve springs etc.) this can lead to extra wear on the engine.

If you have a 5.9 engine..........you should try to stick with the CI-4+ oil and avoid CJ blend. I know they "say" it is backwards compatible. I think it is ho hum oil.......at best. And you definately don't want to go to any extended drain interval with the CJ blend's lower TBN numbers.

..

 

Thanks for all the good info.
A friend has a 93 12 valve and the oil stays clean looking for a long time, is it the extra injection events on the 3rd gens that causes the oil to go black quick with carbon soot?