The engine immediately ran smoother.

This is the first time I've changed the oil in the cummins myself. I read on here that it took a long time to drain. Well, it took that oil cap off and I swear 3 gallons dropped out of that thing in less than 30 seconds, I thought it was going to run over the sides of my oil bucket.

Since Amsoil is more of a detergent than the stock oil....should I run a short drain interval this first time? Or would changing the oil filter after a couple hundred miles be adequate?

 

Been running Amsoil 5-30 since 2nd oil change it is great oil IMO. I have not gone to extended oil changes as yet and am still changing by the manuel but I do the 7500 mile schedule. When waranty is done I may switch to extended oil changes and oil analasis. I would just stick with the regular schedule and not do any short term changes or extra filter changes myself.

 

There is no need to run a shorter interval with a synthetic oil at first. The better way would be to use a engine flush that Amsoil carries while the old oil is in. If you did routine oil changes before you put amsoil in, there should be no reason to do an engine flush. Enjoy the new synthetic and do a oil analysis around 10k to see how the engine is liking it. Don't forget a good oil filter too.

 

Without a doubt on the oil filter.

Put a Fleetguard premium on it.

 

does anyone know why you would run the 15-40 amsoil when the 5-30 amsoil is a better oil ?

 

You're correct in that the additive package is very robust. Since your truck is still practically new, I wouldn't expect much cleaning to be done internally. How long are your OCI's going to be? Are you going to have a UOA done on the oil? Even if the engine had a good number of miles on it with a dino oil, the only thing that I would recommend doing is spinning off the full flow filter at the 7500 mile mark and pre filling the new filter and spinning another one back on.
I wouldn't be doing my job if I didn't interject this......The Amsoil S3K 5W-30 HDD can EASILY be pushed to 15K with only a full flow as long as there is not outside contamination (fuel, coolant ingress, etc..). I ALWAYS recommend a UOA in order to see what shape the oil is in that way you can tailor an OCI that meets your specification.
The AME 15W-40 is a 40 weight.....guys that tow heavy would prefer the added film strength a 40 weight gives. The S3K 5W-30 is a 30 weight, albeit a high 30 weight oil....some folks won't the added protection a 40 weight oil delivers, which is why people still use the 15W-40. Both oils are good.

 

Why is it a better oil?? Who says that?? Amsoil??

 

yes amsoil does say 5-30 is there top of the line or premium diesel oil.something else i have noticed it is amsoils only diesel oil that says in writing it is 100% syn.

 

Arkapigdiesel,

Not sure what my OCI will be, I do plan on doing a UOA at 7500.
I'll proabably take your advice and do a UOA 7500 and change the OF either way.

 

jonesm8,

I switched to Amsoil 5w30 the other day and noticed my engine was a little quieter at idle then the Rotella 5w40 synthetic I took out of it. I also noticed that is was quieter at 55 and 70 MPH! So I can say I was surprised that it is quieter with 5w30 weight oil in it then it was with the 5w40 I had in it. One other thing nice about the 5w oils is you should get a bit better mpg over the 15w oils.

One reason many use Amsoil 15w40 is that's cheaper then the 5w30 oil and some think the 40 weight oil is better then the 30 HDD even thou the 30 has a higher TBN number and additive package. I've read about a semi's using the 5w30 HDD and it's held up so I see no reason why it can't hold up in our smaller CTD.

 

They also have the 0w20, 5w40 Euro, 5w30 ASL oils are 100% synthetic. IIRC all their oil labels say on the bottle that they are 100% synthetic oil. Oh I forgot that the XL oils do not say 100% on the label so I'm not sure what they are.

 

all the oils you said are (auto) oils not diesel rated oils ! the only diesel oil that amsoil makes that says 100% syn. in print is the 5-30 the 10-30 5-40 15-40 -30 weight in the diesel rated oils do not say any where in print that they are 100%syn.( dblr ) amsoil does make a 5-30 oil for autos hope you got the diesel oil it says on bottle for diesels.

 

wrm,

I was responding to your post where you said and I quote once more: “something else i have noticed it is amsoils only diesel oil that says in writing it is 100% syn.”
And my post to you was to let you know that Amsoil has other oils other then diesel rated oil that state they are 100% synthetic on the label or web page.

My self the only Amsoil diesel oil that don’t say they are 100% synthetic on the label or web page, but I think they may be do to the long drain intervals are the ACD 10w SAE30, AME 15w40 and of course their PCO 15w40 being it’s a Synthetic blend. BTW they also have a 10w40 100% synthetic that is API SL/CF, CI-4 Plus rated.


FYI, yes I did use 5w30 HDD Diesel oil on my truck; I've been around diesels for 20+ years so I'm not stupid.

 

(dblr) if you read my post i never said that amsoil did not have oils that were 100% syn. i stated that they only had one diesel oil that said in print that it was 100%syn.in this forum most people dont talk about auto 0ils i just didnt want people to think the oils you listed were for diesels .every body that reads these post has not been around diesels for 20 years. in a earlier post you made you said XL oils did not say 100% but the 10-40 oil that has the CI-4 rating THAT YOU MENTIONED IN YOUR LAST POST is a XL oil. IT IS ALSO NOT CERTIFIED BY CUMMINS AND IS NOT LISTED BY AMSOIL AS A DIESEL OIL.as a mater of fact in most all the amsoil litature it is not listed as CI4+ there are a few exceptions that i could find.but being around diesels for 20 years i know you new all this and were justing testing me .but im not stupid either. lets stick with oils that are for diesels,the other readers might not have 20 years around diesels like you .an they might not be a amsoil dealer like me.

 

Regarding extended oil changes with synthetics, I had a question. I recentley read in a magazine an article about oils/fluids where the author recomended extended changes on diff fluids, tranny fluids, and transfer cases with synthetics.

However, he did not recomend extended oil intervals for the engine oil even with synthetic. He stated that the combustion process in the engine produces a lot of contaminants in the oil (unlike the other vehicle fluids) and the only way to get those contaminants out of the oil is to remove it from the truck....makes sense to my pea-brain. I would like to do long OCI's with synthetics, but I don't want a bunch of garbage suspended in my oil long term.

Any ideas on this? Would the filter change in the middle of the OCI help enough? I don't have a by-pass filter and probably won't get one.