I just bought a 2006 Mega 5.9 4x4 with 13.5k on it and learned that the oil had just been changed before they delivered it to me. 5w30 syn blend was put in...can't remember what brand but it was a basic shop bulk oil.

I don't think the guy who owned this truck before me used it for anything besides running around town. and I've heard that the engines take a long time to break in. so should I chnage the oil to dino oil for the next 7500 miles? or just leave it?

currently getting about 15mpg mixed hwy and city...hand calced.

TIA

E

 

5w30 sounds like gasser oil. Your truck uses API CI-4 rated 15w-40 or 5w-40 synthetic. If they did in fact use standard 5w-30 motor oil, I'd change it out for CI-4+ 15w-40 diesel oil like rotella, valvoline blue, delvac, or similar.

 

If you are correct in what oil was used I say dump it out ASAP. 5w30 or 5w40 synthetic blend oil should not be used in your engine as I personally don’t think it can hold like 15w40 dino oil or 5w40 synthetic oil. The only 5w30 oil that I know that can hold up in a Cummins engine is Amsoil 5w30 HDD. It’s a heavy-duty oil unlike any 5w30-dino oil or 5w30 synthetic blend oils on the market.

JMHO

 

holy crap you're right. just looked at the manual...15w40. why would those idiots put in 5w30? at least that's what the guy told me on the phone when I gave him the VIN to check what was done.

so I guess since I'm gonna dump it anyway should I put in the Rotella dino or go synthetic for the next 7500 miles of break in? or what other brands would you guys recommend? I know Amsoil is popular and I would use it if there is no more break in time left.

going on a 260 mile round trip this weekend pulling my 7500lb toy hauler...so I will change oil before.

really appreciate the heads up on this...I missed it because my other Engine (gasser) used 5/30 and I just figured those guys put in what was right.

E

 

I know some guys will disagree with me, but there is nothing wrong with running synthetic oil on a fresh engine, Cummins or otherwise. It will break-in just fine. I switched mine to Amsoil CJ-4 5w-40 at 1,900 miles.

The most important consideration is that the oil you use is diesel rated. The oil in your engine sounds dubious, so you should probably change it soon. Since you don't have a DPF, you can use CI-4+ or CJ-4 oil. There is nothing wrong with a synthetic blend, as long as it's rated for diesel use. Amsoil and Castrol both make a CI-4+ synthetic blend. For conventional oil, Shell Rotella seems to be a favorite among our DF friends.

 

IMHO Mobil Delvac, Valvoline blue, Delo 400 are very good oils to use for the first 10,000 miles. As for using a synthetic blend, its OK to use it if its 15w40 but not 5w40. IIRC Cummins said that 5w the oil needs to be synthetic and not a synthetic blend. Oh if you have a good heavy-duty full synthetic diesel rated oil you can use 5w30 oil. The reason I say this is because I have Amsoil 5w30 HDD oil in my engine along with oil analyst to back up how well its holding up in my engine.

JMHO

 

I would swap it out before the weekend... I've used rotella (didnt like it) & mobil delvac (liked it) before moving on to amsoil...

 

did you get the truck from a dealership?
check on your reciept, it should say what oil they used before you go dumping good oil.
i'd put my money on the person that you talked to knows less than the techs that worked on the truck.

 

bought the truck from a Nissan/Hundai dealer so I'm not sure about that. I don't have a receipt. the writer I spoke with just looked it up on the puter by the VIN.

I'm just gonna dump it for piece of mind.

E

 

from an import dealer... ya i agree. love my little nissan but your "dump for piece of mind" is just how i would handle that too.