OK, I have been using Chevron Supreme 10w30 in my Kawasaki engines. This a 'dino' oil that has tested very good. But when I went to pick some up for the new 25hp Kawasaki, I found they recently made a change at the store and only carry 5w30 now, which also tests good, but 5w30 is not in the manual. I decided it was too new to put in synthetics, considered other brands, ect. Then I thought "this engine is very new and tight." So I decided the 5w30 would be just fine because of this and the fact that I probably will not even put 20 hours on it before changing it again because the engine is still very young. So I grabbed some for the oil change and to buy time to find somewhere else that stocks the 10w30. But I second guessed myself before changing the oil. So I called around only to find that nobody else in my area has any Chevron oil besides the 15w40 diesel oil... so I'm thinking NOW WHAT? Do I put the 5w30 in for this short run of hours and then choose another oil? Or do I run the 5w30 and forget about it? Or do I choose another oil, run out and get some, then change oil in the morning?