I've been using Delo 400 when I do my oil changes. Today when I bought the oil filter from Valley Freightliner I figured I'd go ahead and give the Mobil Delvac (the only brand they carry there) a try instead of making a separate stop at Walmart to get the Delo, even though the Mobil Delvac was $2 per gallon more expensive.
After the oil change, I noticed an immediate improvement in how smooth the engine ran compared to using the Delo. Also when I shut down, the truck shakes alot less. I never would have guessed that switching oils would have such an immediate and drastic effect.
Has anyone else experienced anything like this? Is Mobil Delvac really that good of an oil? I know that Delo 400 has a pretty strong following with the members here so I guess that's the main reason I wasn't expecting such a radical change.

 

I use Mobil Delvac myself, but Im not sure if you would ever see a difference over Delo 400. Most Wal-marts also sell Delvac, around here its about 60 cents a gallon cheaper than Delo

 

I saw one jug of it, one time in the Walmart here. Never since. Our Walmart isn't even open 24hrs like the majority of them are so I'm not surprised that they don't carry it.

 

Its real good stuff. I use it and run it 10,000 miles.

 

I use either or, whatever is easier/cheaper to get. I have never seen a difference between the two but anythings possible I guess. They are both excellent oils (as well as ro-smella strinky stuff,lol.)

 

I am running rotella in both trucks , and it goes into Every tractor at work (we have it in bulk) and i have never ever noticed an odour?

 

is that valvoline blue any good it has the cummins C on the front label and was wondering if anybody has used it

 

It is the very best , it is cummins certified oil.

 

Ya, the last time I spent forty bucks more for oil I swore it ran better too. It made me feel better....for about 2 days. I guess I'm stuck on that sweet smell of fresh, hot, Rotella!

 

Maybe that's it.

 

We run Mobil Delvac 1300 Super in school buses with DT466s for 12000 miles without a problem, pretty good stuff, just a little harder on the wallet.

 

I made the switch from "Rosmella" to the Premium Blue and it made the same kinda difference in my engine as the Delvac had in Sailpipes truck. I noticed easier and smoother starts when it was cold out and now my oil stays CLEAN!!! With the Rotella it was turning dark and dirty almost immediately after my oil changes, now with the Premium Blue, it's clean still after 2500 miles. It's supposed to have some type of dispersive polymer that breaks down the soot in the crankcase and helps the engine run smoother. I wouldn't have believed it if I hadn't seen it work like it did. From what I've read, it went through some serious testing by Cummins to get their recommendation. I definitely will be using it from now on. Hope this helps

 

What kind of drain interval are you planning?

From Valvolene site (specific reference to ISX and ISM engines)...
"Premium Blue's unique Dispersive Polymer Technology (DPT), which provides advanced soot-fighting capabilities and cold start protection, has allowed oil drain intervals to increase from 15,000 to 20,000 miles (24,141 km to 32,187 km) for severe service, from 25,000 to 35,000 miles (40,234 km to 56,328 km) for normal service and from 35,000 to 45,000 miles (56,325 km to 72,421 km) for light-duty service"

 

Delo 400, Delvac 1300, Rotella T is all the same to me. They are all around $6-8 per gallon.

 

I noted quieter running engines with fresh oil too, and also when using some Exxon XD# Elite, a synthetic blend. The Exxon became unavailable so I started making my own blend with 2 gal Delvac 1300 and 1 gal Mobil 1 T&S. I still notice a quiter engine with fresh oil though.