What type of oil to use for 580SK backhoe?

I'm about to change the oil on my 1992 Case 580SK backhoe. I have an old gallon bottle left from my mechanic that says DELO 400 API CH-4/SM. I bought 3 gallons of Rotella 5T SAE 15W-40 that says meets API service CK-4, CJ-4, CI-4 PLUS, CI-4, CH-4 My manual says to use 10W-30 API CE, CD, CC/SG. The 10W30 shows a range of -25 to +25F. I mostly run this backhoe in temps above, say, 10 degrees F but it does get colder than that where I am and am now using it to plow snow. The majority of the time it gets run is during warmer temps. Temps could get colder than that. I ran this question through Chat GPT and it says some of the newer API specs are backward compatible but it's important to go with what the manufacturer states. What do you all run in yours?

I have a 580K,I run 15w-40 Rotella works good for me.

Hi, Steve, Do you use the Rotella T5 or T6?

Yikes,I think T6.

Of course! I bought T5....

It won't matter.

cmrsf1 said:

Of course! I bought T5....

Click to expand...

Stop worrying about it. T, T5, T6, they'll all work just fine. I personally would prefer the 5 over the 6 because of the age of the engine. Keep an eye on it after changing, if you have consumption issues, you might consider a different brand. I've personally seen engines that don't like Rotella for some reason.

Of course, Dave beats me by a second.

cmrsf1 Im sure I’ve probably used both lol,never had a consumption issu.