Need help and opinions on diesel engine oils

[Rat Rod Mac]

I have been using Conoco T5X Heavy Duty SAE 30 weight diesel engine oil for the past ten years, and to be perfectly honest have had no problems. But now my drum is empty and I have a decision to make. I was running this oil in an old dump truck with a gas engine, and an older tractor with a diesel engine in it that I hardly ever used it in the winter time. Now I have picked up a Kubota with a diesel engine that I will be running in the winter time. I see Rotella offers a 15W-40 that maybe an option. The Conoco and the Rotella are "conventional" oils. No synthetic base in them. Everyone I know seems to think the synthetic blends are the way to go (the wave of the future, I'm old fashion). Now here's my question,,, the Kubota calls for 10W-30, would running the 15W-40 have any detrimental effect on the engine especially in the winter time? Would it be fine to use this grade of oil? I'm thinking the 15W-40 would be better than running the straight 30 weight in it. I also think that if you change your oil and filters regularly you don't need synthetic, or do you think I should switch over to a synthetic or a synthetic blend? You guys have any experience along these lines I sure would like to hear them. Do you have any favorite oils that you prefer over others? Thanks in advance. RRM

 

[Peter 315]

I run 15/40 in my kubota mobil super delvac 1300 all year

 

[sixdogs]

What I've done is go synthetic and change oil half as often. Synthetic starts so much easier, is easier on the engine and lasts longer. Kubota may call for 10W30 but has now amended that to OK with 15W40. Synthetic is 5W40 and Rotella T-6 is a good start. Nothing wrong with conventional oil in the summer only but life is so much easier in colder weather with synthetic.

 

[bdog]

Where do you live? 15w40 is great year round in Florida but probably not in Alaska. 10w30 is not specified by a lot of manufacturers in ambient temps over 100 degrees. Conventional oils are fine and I used to run 15w40 in everything but I travel up north sometimes in the winter and when it gets around 10 or below you start to notice a huge difference it starting ease between 5w40 and 15w40.

We have ran our equipment in single digit temps with 15w40 and didn’t hurt anything but we tried 5w40 and starting was much easier and it from my understanding gives the same protection at high temps as well, probably even better because it is synthetic. So now I use synthetic. Not because I think I need it to make my engines last or because I extend my change intervals I use it solely for the performance in a wide variety of temperatures.

Any major brand is good. I have used rotella, delo, delvac and Deere all with no complaints. I am currently using Schaeffer and buy it by the drum and they deliver to my house. I use about 1.5-2 drums a year depending on how busy we are. If I never left home where it very rarely drops below 20 I would just use 15-40. If it didn’t regularly get over 100 or even 110 where we sometimes work I would probably use 10-30

 

[Sawyer Rob]

I run 15w-40 Rotella year around in most of my equipment and it does, at times, go below 0 here in the winter...

I've been using it for many years and I've never had an oil failures of any kind...

SR

 

[Rat Rod Mac]

I'm located in Northern Ohio, so I'm thinking the 15W-40 may work out just fine. I want to thank all of you guys for your help with my concerns about toil situation. Thanks. RRM

 

[Oldoak]

I've been running 15W-40 Rotella year round here in NE PA for years. I also never found a need or have been convinced to use "full synthetic" oil.

I change my engine oil and filters once a year on all my machines no matter what the hour meters read. None of which have ever run over the oil change intervals stated in the owners manuals.

 

[Rustyiron]

I have been using Conoco............ Everyone I know seems to think the synthetic blends are the way to go (the wave of the future, I'm old fashion)................. I also think that if you change your oil and filters regularly you don't need synthetic, or do you think I should switch over to a synthetic

I'm with you RRM. Unless you have a special by pass filtering system for extended oil changes, I want that black chit out of there. And even doing 100 hr. change intervals with TSC or any oil meeting the spec, along with new filters has to be better (and still cheaper) than these "dreamer" change intervals. I believe they are mostly claims from those selling it and the manufactures claims for cheaper maintenance costs on their product for a sales advantage. By the time you have an oil related failure, you're out of warranty and good luck proving otherwise to them.

 

[747driver]

I run 15/40 in my kubota mobil super delvac 1300 all year

Same thing I run....as I also use that in the motorhome.

 

[Texasmark]

Delvac, Delo, Shell Rotella T all have Compression grade 15w-40 dino oils and I know Shell has 5w-40 full syn because that's what I use in my Bransons. I run Wally World, 15w-40 in myFords.