Best engine oil for 12 valve cummins

[Zombie]

I've read so many articles and seen three different grades recommended by auto parts stores, and I've got a little bit of analysis paralysis going on. I figured, what better way to cut through the noise than to ask some guys who live close to where I live, and might have some real world experience with making a similar choice of oil.

The truck is a 98 12 valve X cab short bed. I don't tow anything these days, occasionally haul stuff, but mostly just drive the snot out of it. I don't think I'm an abusive driver, but I do love the sound of the turbo whistle, and I'm not exactly easy going either.
Engine wise, the truck has some timing, a modified hot side from Banks with the big head waste gate, banks intake manifold and fuel plate, and a 4"exhaust. As far as I know the delivery valves are stock, but there are several indicators that the injectors might be aftermarket (waiting to hear back from the original owner).

As I near my first oil change, I've realized I don't know what weight I should use for our climate, or what brand the cool kids run these days. So I figured, why not ask the RME brain trust? So, I'm asking.


Obligatory pic so maybe I'll end up in a spotted thread someday.

 

[TRD270]

Copied what the company I drove for used. Was OG Rotella don’t remember which one exactly but fairly certain 15-40 in summer 5-40 in the winter. Trucks had 300-800k on them so I assume they liked the oil

 

[shortstraw8]

Pretty sure cummins suggests valvoline premium blue 15w 40 for that motor but I think any decent 15-40 should do and really anything with higher zinc is better.

 

[skippy]

In every single one of my cummins trucks I have ran a full synthetic 15w40. Not really loyal to any brand as long as its full synthetic

 

[Mouse]

Sharp truck

 

[ID Bronco]

My wife's Uncle pulled me aside at our reception to talk cars, and he told me clean oil is the best oil for cars. Change it religiously.

I have a similar Cummins so I appreciate the feedback too.

 

[glockman]

My kid has been beating the ever living hell out of a 24v Cummins that is heavily modified, has compounds and will peg a 60psi boost gauge. He has broken 3 transmission input shafts if that tells you how it's driven. It has 270k miles on it and for the last 100k it's got valvoline, delo or rotella. I don't think he has a preference. Recently with diesel oil, it's kind of what you can get your hands on. It's better now than it was 3 months ago but still pretty hard to find some flavors.

 

[Zombie]

Thanks for the feedback, gents. One remaining question is around running a different weight in the winter - I don't put a ton of miles on this truck, so if I run a change interval of April and October, I'd probably be changing it at around 4K miles on the oil. Would running a different winter weight be a good idea?

The truck does have a block heater, and my plan is to plug it in as soon as it starts getting cold at night - I'd love to set up a routine with a smart plug to have it automatically turn on below a certain ambient temp, between the hours of 1:00 AM and 7:30 AM, but I'm not sure what that temp should be... what's too cold ambient?
Is there any hard that can come from running the block heater if it's too warm?

Yeah, I'm a noob with this stuff... kind of embarrassing really, but I've never actually owned a diesel before... worked on a bunch of them, including this one, but never owned one until this year.

 

[bryson]

I ran 15w40 year-round. Conventional because I'm cheap, but nowadays, you won't have many conventional options, and the synthetic has come down in price, so I'd run whatever 15w40 synthetic you find on sale.

As for the block heater, you won't harm anything on the truck/engine to run it if it's "too warm" - maybe risk burning out the heating element, but it's not really a big deal to replace one either. I plugged mine in pretty much anytime it was below freezing outside. Never had any issues. This is with both 5.9 Cummins and 7.3 Power Strokes.

 

[shortstraw8]

With a block heater you shouldn't have any issue in -˚temps, even with out it just let it warm up for a bit or take it easy for the first little bit of driving as you should anyway to let the tranny fluid cycle imo.
I don't recall issues in the winter with our 5.9s for work when we weren't able to plug them in, just like any machinery let it warm up and cycle the oil should be no issues.