When the US has oil again. What should I buy?

[Clarkst]

I bought a 2014 Seneca, cummins 6.7 and I want to change all the fluids. I am not finding consistent info on the proper oil. Synthetic, conventional, I thought with the high milage intervals it would have to be Synthetic, but see rotella T4 recommended on some sites.
What do you all use?
Thanks.

[Midnightmoon]

Any modern CK-4 spec diesel oil will meet the requirements of your B-Series Cummins. Popular brands are the Rotella you mentioned, as well as Mobil Delvac, Valvoline Premium Blue, etc. I wouldn't get too hung up on specific brands at this current time. A fresh change with whatever quality oil you can find at the moment will be more than acceptable.

When the selection eventually increases, you can then switch to your brand of choice.

[Lake Huron]

If I remember right, a Cummins was designed to run on Valvoline Premium Blue. That's what I ran in my 99 Cummins. At one point I switched it over to Amsoil and ran that for a long time but found with the heavy modifications I kept doing to the engine the oil was getting too dirty too fast, even with a bypass system installed. So I went back to VPB and changed it more frequently.
My Current Duramax is bone stock as far a horsepower mods and I run Amsoil in it with a bypass system installed. Amsoil has always been available whenever I place my order and its shipped out and at my door within 2 business days. It may cost a little more than the store shelf stuff but I'm not spending $4.45 for gas or $5.45 for diesel, and my time having to drive all.over the place shopping for oil.

[Clarkst]

Thank you for the information. Would you recommend full synthetic?

[Lake Huron]

My $.02, I would recommend full synthetic.
I'm not one of those people that's going to stand on the Amsoil soapbox and say it's the best, bla, bla, bla..
However, Amsoil was like the first to introduce synthetic oil back in the early 70's, which most thought was "snake oil" but has proven it's full synthetic line of oils outperform other oils. Slowly over time its gained popularity and companies did their own research and found full synthetics actually do work better and started to get in the full synthetic market.
It seems as time goes on more and more manufacturers suggest, and sometimes even require, a full synthetic oil to be run in their equipment.
What's even more important than the difference between conventional vs synthetic oils are the filters used to keep the oil clean. Best full synthetic oil out there won't be worth a crap if you're using junk filters.

[Rustynuts]

Oil choices are all a personal preference and probably one of the most argued subjects on the internet As long as it meets the manufactures specs you are good. Cummins does state synthetics May be used but not before the first 15k miles. Personally, I run Rotella T4 15-40 in all my diesels and also the generator.

[Clarkst]

Understood. I was an early adopter of amzoil, had it in my 69 beetle!
I have used synthetic in all vehicle I have owned since the mid 90s. I didnt know if the milage interval recommended oil changes meant by default you had to use full synthetic.
Because I could not find any full synthetic, including amzoil, I ordered Rotella T4, met cummins oil spec. Now in search of a filter.....

[Midnightmoon]

Originally Posted by Clarkst

Understood. I was an early adopter of amzoil, had it in my 69 beetle!
I have used synthetic in all vehicle I have owned since the mid 90s. I didnt know if the milage interval recommended oil changes meant by default you had to use full synthetic.
Because I could not find any full synthetic, including amzoil, I ordered Rotella T4, met cummins oil spec. Now in search of a filter.....

Take a look at Geno's Garage for your Cummins parts if you can't find them locally. The will have both Fleetguard and Mopar branded filters available.
https://www.genosgarage.com/category/oil-filters

[Rustynuts]

Originally Posted by Clarkst

Now in search of a filter.....

Here is what I use on mine.

Engine Oil Filter Fleetguard LF3970
Engine Fuel Filter Fleetguard FF63009
Engine Filter/Water Separator Yours is different than my S2 chassis.
Engine Air Filter Donaldson P607955 Air Filter, Primary, Powercore
Crankcase Breather Filter Fleetguard CV5200100
Cabin Air Filter Wix 49082

Generator Oil Filter Cummins Onan 122-0833 - Napa Gold 1064
Generator Fuel Filter Cummins/Onan 147-0860
Generator Air Filter Cummins/Onan 140-2897

[CAG]

And the oil debate goes on and on.


While I have used exclusively Amsoil for years there are those who subscribe to the "oil is oil" club and that's pretty hard to argue. The proper weight, as called for in the manual, is more important than the brand. Send a sample off to Blackstone every third change, or so. It's as important as the blood tests your doctor orders for you.


I said in another of these long oil threads that diesel oil dirties faster than gas engine oil because of the high compression of the diesel engine which causes more blow-by. A little more complicated than that but the short story. Test the "dirty" oil and you will likely find it is still doing it's job.



Additionally, do your homework on filters. They are most times more important than the oil itself and some of them are garbage.


And yes on synthetic!

[Clarkst]

Originally Posted by Rustynuts

Here is what I use on mine.

Engine Oil Filter Fleetguard LF3970
Engine Fuel Filter Fleetguard FF63009
Engine Filter/Water Separator Yours is different than my S2 chassis.
Engine Air Filter Donaldson P607955 Air Filter, Primary, Powercore
Crankcase Breather Filter Fleetguard CV5200100
Cabin Air Filter Wix 49082

Generator Oil Filter Cummins Onan 122-0833 - Napa Gold 1064
Generator Fuel Filter Cummins/Onan 147-0860
Generator Air Filter Cummins/Onan 140-2897

Thank you Rusty. This information is very helpful to us, thank you for taking the time to respond and share.

[Clarkst]

Originally Posted by Midnightmoon

Take a look at Geno's Garage for your Cummins parts if you can't find them locally. The will have both Fleetguard and Mopar branded filters available.
https://www.genosgarage.com/category/oil-filters

Thank you Midnightmoon, going to Geno's now!

[Clarkst]

Originally Posted by Lake Huron

My $.02, I would recommend full synthetic.
I'm not one of those people that's going to stand on the Amsoil soapbox and say it's the best, bla, bla, bla..
However, Amsoil was like the first to introduce synthetic oil back in the early 70's, which most thought was "snake oil" but has proven it's full synthetic line of oils outperform other oils. Slowly over time its gained popularity and companies did their own research and found full synthetics actually do work better and started to get in the full synthetic market.
It seems as time goes on more and more manufacturers suggest, and sometimes even require, a full synthetic oil to be run in their equipment.
What's even more important than the difference between conventional vs synthetic oils are the filters used to keep the oil clean. Best full synthetic oil out there won't be worth a crap if you're using junk filters.

Thank you Lake Huron, I would prefer full synthetic, but fresh fluids and filters are the idea.

[Clarkst]

Originally Posted by CAG

And the oil debate goes on and on.


While I have used exclusively Amsoil for years there are those who subscribe to the "oil is oil" club and that's pretty hard to argue. The proper weight, as called for in the manual, is more important than the brand. Send a sample off to Blackstone every third change, or so. It's as important as the blood tests your doctor orders for you.


I said in another of these long oil threads that diesel oil dirties faster than gas engine oil because of the high compression of the diesel engine which causes more blow-by. A little more complicated than that but the short story. Test the "dirty" oil and you will likely find it is still doing it's job.



Additionally, do your homework on filters. They are most times more important than the oil itself and some of them are garbage.


And yes on synthetic!

Thanks, I had neglected filter research for many years. A bit of research made it clear I had been using the wrong filter brand for years.

[Lake Huron]

Originally Posted by Clarkst

Snip..
Because I could not find any full synthetic, including amzoil, I ordered Rotella T4, met cummins oil spec. Now in search of a filter.....

If you were shopping for Amsoil on a shelf in a store somewhere, that makes sense as to why you couldn't find it. Pretty difficult to find it in a store, and if you do I doubt they'll have the quantity you'll need.
I have yet to place an order with them and they NOT have anything in stock at the warehouses.
If they run out of oil in the warehouses, that's not good. Lol!

[CAG]

Originally Posted by Lake Huron

If you were shopping for Amsoil on a shelf in a store somewhere, that makes sense as to why you couldn't find it. Pretty difficult to find it in a store, and if you do I doubt they'll have the quantity you'll need.
I have yet to place an order with them and they NOT have anything in stock at the warehouses.
If they run out of oil in the warehouses, that's not good. Lol!

Amsoil has never not had what I need when ordering. I switched to Costco oil for the last oil change on the Jeep just to see if their synthetic was that good but I seemed to have noticed more lifter chatter than before. I am going to switch back to Amsoil with the next one to compare. Bottom line is I just have not found anything that does the job that Amsoil does. More expensive, yes but you can run longer intervals if you want and just have that peace of mind. Change the filter at oil change time, add a quart of oil and go for another 10K miles. Put a Fumoto valve in the pan and draw a sample for Blackstone to be sure the oil is still good. Onward and Upward!


Also to those who rag on Amsoil because it does not have all of the fancy letters behind the approvals. Think Magnuson-Moss Warranty Act. It makes no difference. The motor company has to prove that what you put in the engine cause a problem you have, and they have never been able to prove that with Amsoil!

[Clarkst]

Originally Posted by Lake Huron

If you were shopping for Amsoil on a shelf in a store somewhere, that makes sense as to why you couldn't find it. Pretty difficult to find it in a store, and if you do I doubt they'll have the quantity you'll need.
I have yet to place an order with them and they NOT have anything in stock at the warehouses.
If they run out of oil in the warehouses, that's not good. Lol!

On the website they have a disclaimer with a list of reasons they may not be able to fill the order.

[CAG]

Originally Posted by Clarkst

On the website they have a disclaimer with a list of reasons they may not be able to fill the order.

My guess is they all do and many businesses lately have those same stocking problems, but that aside my orders have always been filled and shipped within a day or two.

[Clarkst]

Originally Posted by CAG

My guess is they all do and many businesses lately have those same stocking problems, but that aside my orders have always been filled and shipped within a day or two.

Fair point.

[Billandcarole]

Stop by a Truck Stop and buy it by the Gallon Jug. The big Diesels in the Tractor-Trailers go by Gallons, not Quarts....How do I know this? I'm a retired Tractor-Trailer driver. Good Luck, Happy Camping!...My Series 60 Detroit Diesel took 10 Gallons of Rotella.