Read the little book that comes with your small engine-powered machine. If it says 10w30, run 10w30. The brand of oil would, of course, be an entirely different animal. If you think Mobil 1, synthetic, gold dust enhanced, twiced blessed by a Rabbi oil is the best, then use it. Just make sure it's 10w30. Manufacturers are taking a hard line on warranty claims when the "suggested" maintenance and fluid requirements aren't being followed to the letter. Times is hard and the fact that some of the traditional industry leaders are churning out junk to cut costs leads me to believe it would be very hard to get warranty work or replacement on something you didn't follow the directions on. The more denials of warranty, the more money in their pockets.
I do have a question for the oil heads (in all seriousness). If an oil lists parafin as one of the ingredients, is that a bad thing. I'm not an oil guy but would like make sure I'm not putting complete garbage in the small engines that come through my shop. I'm embarrassed to say what kind I use. Can you folks enlighten me? Pardon my ignorance.