You can use what ever you like. If you check your Kawasaki manual it will say or give you Oil Type as Detergent Oil (API service SF, SG, SH, SJ, or SL) it also will tell you the use of a Multi-Grade Oils (5w20, 10w30 or 10w40) will increase oil consumption and to check the oil levels more frequently. You should choose your oil according to the table listed in your manual. You can't google for an answer to your question because there is none, using a synthetic over the conventional oil is a personal choice at twice the price.
I disagree Ric, read the following:
403 Forbiddenclick anyway.
Really, You want me to believe someone who's keeping a B&S blog that's promoting there B&S oil over my Manual/Manufacturer and what they recommend I use . It's just his opinion. Besides he said the same thing I did, Our engines are designed to run on
conventional oil, full synthetic, or synthetic blends. It痴 an owner痴 personal decision if he thinks the extra cost is worth it. Now I will say B&S needs every advantage to keep there engines/ :smile: (said politely) running.
The thing is with all the talk about synthetic oil and its testing it's always about extending your oil changes up to 15K and how great the stuff is according to there tests on a car, truck, suv or van, it's all hype imo. I extended my oil change, i got 4328 miles instead of 3000 miles on my first synthetic oil change on my truck
that's when the computer said change oil soon, even the dealership says change the stuff every 5000 miles.