</font><font color="blue" class="small">( I have a Kubota 2910 w/ @ 55hrs on it. I want to switch to Mobile 1 because that's what I run in my automobiles but I'm not sure if it's the best for a diesel. Any comments? )</font>
Asking "what is best" is a loaded question.
The bottle of mobil 1 in my garage says it is "API SJ/CF".
The manual for my kubota B7200HST says it wants "API CC or CD rated oil".
I would read that as mobil 1 is fine for my kubota. You should check the manual for your tractor to see if a CF rating is sufficient, and if so, then mobil 1 should be just fine in your kubota.
I personally run Delo 400 in mine. It is API CI-4, CH-4/SL rated. That is a higher rating for both gasoline AND diesel motors than Mobil 1, and it is a heck of a lot cheaper. I buy it 6 gallons at a time at costco. I pay a little more for it than the gasoline only oil, but it reduces the number of different oils I have to keep in the garage. It is also, and more importantly, the least expensive heavy duty motor diesel motor oil I can conveniently purchase around here.
I still run mobil 1 in my air cooled engines. Partially because I believe the additive package in it will handle the excessive heat of an air cooled engine better than some other brands. Partially because I bought 6 quarts of it 2 years ago and haven't used it. And mostly because I buy 15w40 for my car/truck/tractor and briggs and stratton warn aginast 15w40 in their air cooled engines.
So, in summary. I don't see any reason you couldn't use mobil 1 in your kubota as long as the kubota is happy with a API CF service rating. Asking whether it is the "best choice" opens another can of worms /forums/images/graemlins/smile.gif