In lower Michigan, operating temps. will be 40 to 85 F +/- 5 degrees on occasion. The manual says 10w30 or 30 wt. SJ, with the caveat that the 10w30 may increase consumption (combustion chamber buildup too?) So, the manual leans me towards the 30wt. SJ. Am I correct? That's such an old oil spec. and I wonder what experience others have had following it. Are the Kawasaki's a cam/lifter design such that they run better on the high additive levels of an SJ oil vs. that of a modern SM oil? Would not a Heavy Duty Diesal/Gas Oil like SJ Rotella 30wt. be best? Has anyone tried Amsoil's somewhat new 30 wt. small engine oil that also qualifies as a 10w30? Thanks in advance.