560 Engine Oil

I am going to change the oil in my 560 (first time). The manual says to use a 30W oil. Simple, right?

Well, a friend of mine says to be sure to use a 30W *diesel* engine oil. And I see TSC has diesel engine oil. Another buddy (who has several diesel tractors) says he just uses 30W car motor oil.

So...do I really need the diesel oil?

Is the TSC brand (Traveller) good or would you folks recommend a name brand oil? If the latter, which one?

Thanks for the advice.

35 years ago I was running 9 tractors, 4 trucks, a car and an assortment of small engines. I was using 3 kinds of oil, and having employees, the proper oil did not always go where it should. Simple fix was use one kind of oil. I went with diesel type and back then 30W in summer and 20 in winter. Since that time I have switched to 15W-40. I have used both oils in every vehicle from a 560D, 1066, Super A, Chevy pickup both gas and diesel, Buick and even my 4 cycle lawn mower. The lawn mower has always mowed a 1/4 to 1/2 acre. It was given to me by then IH dealer in 1975 when I purchased the 1066. The engine is original. In all those years I've never experiences premature failure of an engine. Couple didn't last as long as I thought they should, but I wouldn't call it premature failure.