HeadedToTexas
Guru
I’m preparing for my first solo oil change and need 4 gallons of appropriate 15W-40 per my Cummins manual. What is the best source, and is 15W-40 oil 15W-40 oil, or do common rail diesels need special oil?
Best source of 15W-40 for my Cummins QSB
- Thread starter HeadedToTexas
- Start date
The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
If you have answers, please help by responding to the unanswered posts.
psneeld
Guru
is the engine under warranty? that really only matters if you care to use OEM recommended.
Otherwise, I have been using Rotella 15W40 for 30 years with no issues.
Walmart by far the least expensive I have found.
Otherwise, I have been using Rotella 15W40 for 30 years with no issues.
Walmart by far the least expensive I have found.
Make sure the oil is diesel rated 15W40 oil and the API rating matches what the manual requires. I always use a big named brand oil, Shell, JD, or Chevron Delo but any oil that matches the specifications in the manual will work.
For information on API ratings, this link I quickly found might help, https://petroleumservicecompany.com/blog/new-engine-oil-specifications/
I buy oil at Walmart, my tractor dealer, and various auto parts stores. Which ever has the best price. Our local Costco does not have diesel rated oil I could use, which is odd, but if they had it, and the price was right, I would buy it.
I get my used oil tested at https://www.blackstone-labs.com/ One does not need to do the testing but I like to have the test results.
Later,
Dan
OP
OP
HeadedToTexas
Guru
My QSB 380 is a 2007 and long out of warranty; it’s just my first oil change.
There is a big price difference between Rotella T4 and T6. What’s the difference in the product?
There is a big price difference between Rotella T4 and T6. What’s the difference in the product?
OP
OP
HeadedToTexas
Guru
Excellent article, Dan. That’s what I was after. Thank you.
OP
OP
HeadedToTexas
Guru
The Cummins manual indicates oil must meet CG or CH specs. Guessing those have both been surpassed by several API updates.
GoneDiving
Senior Member
15W-40 Diesel oil is different to 15W-40 oil for gas engines. It will be written on the drum and the two are normally grouped separately on shop shelves
Personally, I stick with name brands rater than saving $5 for no name discount store knockoffs. Shop around as prices vary widely for the same product from different suppliers and sales or discounts are common.
You are changing the filter at the same time, yes?
T4 is the regular oil and T6 is a full synthetic oil.
Using regular engine oil vs a synthetic depends on your needs. I use synthetic oils in my truck and tractor for a variety of reasons but one is the ease of starting when the engine is 40F degrees or colder. Not sure you will have that issue on your boat.
EDITED: I should have also mentioned, to be clearer, that using a semi synthetic or synthetic engine oil, during cold weather allows me to NOT have to use an engine block heater. The engine block heater for my truck pulls quite a bit of power and ends up costing about $20 a month which pays for the extra cost of the oil.
Using a non synthetic engine oil that meets the manual's specifications works just fine.
Later,
Dan
Last edited:
Comodave
Moderator Emeritus
- Joined
- Jul 2, 2015
- Messages
- 21,284
- Location
- Au Gres, MI
- Vessel Name
- Black Dog
- Vessel Make
- Formula 41PC
Where I live there are not any good sources for oil so I usually get it from Amazon.
firehoser75
Guru
- Joined
- Feb 18, 2018
- Messages
- 1,705
- Location
- Canada
- Vessel Name
- former owner of "Pilitak"
- Vessel Make
- Nordic Tug 37
In my Cummins 6BTA, I used Rotella T4 full Dino. Meets all the specs, and always changed it (and the filter) before recommended hours interval, sometimes mid-season.
Check your exact engine's manufacturer's requirements, but I am reasonably sure that the Dino oil is "all you really need".
One of the reasons for synthetic is the ability to "go longer between changes", but for most boaters, they change only once per year anyway, usually before the "hours" are reached (at the end of season), so no big advantage in that regard.
Your boat, your money.
Check your exact engine's manufacturer's requirements, but I am reasonably sure that the Dino oil is "all you really need".
One of the reasons for synthetic is the ability to "go longer between changes", but for most boaters, they change only once per year anyway, usually before the "hours" are reached (at the end of season), so no big advantage in that regard.
Your boat, your money.
FF
Guru
- Joined
- Oct 12, 2007
- Messages
- 22,552
The key to oil selection is to use a brand you will be able to find most anywhere , to avoid mixing brands.
Rotella T is pretty common.
Rotella T is pretty common.
OP
OP
HeadedToTexas
Guru
Thanks folks, Rotella T4 it is. Found it on the shelf in each place I looked as well as on line. Filters will get changed too, but I already have those in inventory.
FF
Guru
- Joined
- Oct 12, 2007
- Messages
- 22,552
"Filters will get changed too, but I already have those in inventory."
Filters are expected to be used rather quickly after being manufactured, so are not rustproof.
Keep the lube oil and fuel filter inventory in a vacuum sealed bag for cruising..
One question is how much lube oil should be carried onboard.
The biggest engine flooding risk probably comes from the usual wet exhaust.
Sailing I used to carry 3 full oil changes , just in case
Filters are expected to be used rather quickly after being manufactured, so are not rustproof.
Keep the lube oil and fuel filter inventory in a vacuum sealed bag for cruising..
One question is how much lube oil should be carried onboard.
The biggest engine flooding risk probably comes from the usual wet exhaust.
Sailing I used to carry 3 full oil changes , just in case
Last edited:
