Mobil 1 Diesel 5W-40 Engine Oil in my L39

[jlrsn]

After reading about Mobil 5w40 Turbo Diesel Fully Synthetic Engine Oil on this forum and further online research I decided to give it a try in my Kubota L39 TLB. My shop where I store my tractor was heated until the snow and ice sheared off my shop heater exhaust stack (again).

Nightly freezing temperatures that are quite often below 0 degrees F in the winter was a concern as most engine wear is during startups until the oil flows freely. While my shop was heated I originally was using Delo 400 Multigrade 15W-40 Oil that I've used in my 7.3L Turbo Powerstroke since it was new but after I lost my shop heater I decided to use Mobil 10W-30 CF API Rated Fully Synthetic Engine Oil in my L39.

A few days ago I drained the Mobil 10W-30 CF API Rated Fully Synthetic Engine Oil and refilled with the Mobil 1 Turbo Diesel Truck 5W-40 Fully Synthetic Engine Oil. As I was pouring the 5W-40 Engine Oil into the funnel at 5 degrees F shop air temperature I was amazed at how it flowed like water on a hot day! The first start was very smooth and very quiet and my cold engine appeared to actually idle faster and quieter than when the engine was warm with the 10W-30 Oil

This spring, when it arrives, I'm going to run my shop's overhead forced air propane heater exhaust stack out the back wall instead of through the roof. I say when spring finally arrives as I've had 6" of snow fall on the 15th of June.

I keep my battery charged using a Battery Tender and I treat my fuel with Stanadyne Performance Formula. My L39 has a block heater which I use for really cold starts.

Jim

[RWEST]

I've never used M1 5-40 Diesel, but do use Rotella 5-40 and J-D 0-40, and am very pleased with the cold start-ability, compared to the standard diesel 15-40's. My garage is unheated, and the first time I started my tractor up in sub-freezing temps after changing out the 15-40 that was in it, I was just astounded at the difference. We run the wide-range syns in everything now...

[RalphVa]

I don't understand why some are still using the 15w40 stuff with 5w30 and 5w40 stuff available. I use 0w30 Mobil 1. It's not heavy duty diesel rated, but I change after only about 100 hours vs. the 200 recommended by JD. Even 0w30 will be heavier at startup, even in summer, than a 15w40 at operating temperature. So, there's no danger in being too light at startup.

I got 1 more mpg in our 1983 240D with 0w30 vs. 5w40.

Ralph

[jlrsn]

I don't understand why some are still using the 15w40 stuff with 5w30 and 5w40 stuff available.
Ralph

Hi Ralph,
Your postings, background, and my online research is the main reason I went with the Mobil 1 Diesel 5W40 Fully Synthetic Engine Oil in my Kubota L39. I'm still amazed as to how smooth and quiet cold starts and idle are now as compared to cold starts when I was running Delo 400 Multigrade 15W-40 Engine Oil in my L39.

I still use Delo 400 Multigrade 15W-40 Engine Oil in my F250 PSD, Mobil 1 MX4T 10W-40 Engine Oil in my Kawasaki Brute Force 750 ATV, Mobil-1 15W-50 Fully Synthetic Engine Oil in my BMW Motorcycles, Mobil-1 Tri-Synthetic Formula 10W-30 Fully Synthetic Engine Oil in my Jeep Grand Cherokee Limited 5.9, plus I'm just now realizing I used all Mobil Lubricants in my Turbine Aircraft and all my Bridgeport Vertical Mills and Lathes, etc. I should have bought shares of Mobil!!! Old habits that work well are hard to break sometimes!!

Take care,
Jim

[ModMech]

I don't understand why some are still using the 15w40 stuff with 5w30 and 5w40 stuff available.

I cannot say what others are thinking in theor own minds, but unless you operate in a COLD climate, there is no reason to use the lighter oils. The 15W-40 will protect the turbo and rotating assembly better in HOT climates, so that may be a factor as well.

I use 0w30 Mobil 1. It's not heavy duty diesel rated, but I change after only about 100 hours vs. the 200 recommended by JD.

If it's not CI-4 or CJ-4 rated, DO NOT use it in a diesel, you can "stick" the pistons rings with automotive oils and the chemicals in automotive oils are not what is needed in a diesel. that is why there are seperate ratings for Spark Ignition (SI) and Compression Ignition (CI) oils.

Even 0w30 will be heavier at startup, even in summer, than a 15w40 at operating temperature. So, there's no danger in being too light at startup.

Ralph

That's not true, not at all. 15W-40 IS 15 Wt oil with "viscosity improvers" to obtain the 40 wt viscosity rating at 100*C. Equallly, 0W-30 IS 0Wt oil with VIs to achieve the 30wt rating at 100*C. I'm pretty sure everyone understands that "straight weight" 30 is "thicker" than 0Wt oil (machine oil) at ANY temperature and the colder it is, the more pronounced the affect.

[dieselfreak]

I don't understand why some are still using the 15w40 stuff with 5w30 and 5w40 stuff available. I use 0w30 Mobil 1. It's not heavy duty diesel rated, but I change after only about 100 hours vs. the 200 recommended by JD. Even 0w30 will be heavier at startup, even in summer, than a 15w40 at operating temperature. So, there's no danger in being too light at startup.

I got 1 more mpg in our 1983 240D with 0w30 vs. 5w40.

Ralph

Warranty would be a good reason. I am still researching, and the MF 1635 I looked at called for 10W30. WOuld running 5w40, if a problem occured, cause a warranty issue??

df