dlundblad said:15w40 and 5w40 for my diesel tractors as well as my dads.
My new Kubota is approaching it's initial 50 hour service and I'm not sure what oil to use. The manual is outdated and states 10w30, 15w40, SAE 20 and SAE 30 depending on the temperature. I'd prefer to use 5w40, but I don't want any warranty drama should an issue arise. Will most likely run 10w30, but the darn thing has a 7 year warranty. Lol.
I went through the same thing with my Kubota le3560hstc.I ended up running 10w30 for winter and will switch to 15w40for summer mowing.Oil is cheap.
I've got some Mobil 1300 15W40, that I'll be using in a Taurus (was originally bought for a different car). I keep reading that the 1300 is "semi-synthetic", but doesn't say that on the bottles I've got. I just got it a few months ago, says CK-4, so it's not some really old stock they gave me. Where does it say semi-synthetic?
All of the diesels in my fleet are Powerstroke 6.7s. Our bulk oil has been Mag1 5W40 for several years. Recently purchased Purus 5w40 but also still buying Mag1. Bought the Purus to save money. Had zero issues with the Mag1. Just had a rep drop off 10 gallons of Duragard Diamond Shield 5W40 to try. Will be going in three of my trucks tomorrow. He offered to pay for an oil analysis of my current oil at 0% OLM and then another analysis from the same truck with the Duragard at 0% OLM for comparison. I’m going to take him up on it. He swears I will be amazed. Never done any OAs Never seen a reason to spend the money. Oil is oil is if meets specs IMO.
Duragard claims to be only true 100% synthetic 5W40 Ford Approved HDEO on the market. It’s also very inexpensive. We will see. I will share the OAs in the forum. They state the oil is true 100% synthetic. Don’t really think it matters but free oil is free oil and it meets Ford Spec per Ford webpage.
I'm intrigued By full syn 15W40 bc I’m in the southern part of Florida. Never gets cold. But the owners manual states for heavy duty use to use only a 5W40 so that’s what I’ve always done. Doesn’t matter. Never had any problems. My trucks run hard and haven’t had any oil related failures. Ever.