I have a new Dixie Chopper Zturn with a 23hp Kohler. Kohler recommends Kohler 10w30 but Dixie Chopper recommends Lucas 15w40. I did my 10 hour oil change as recommended by the dealer and used a Kohler filter and the Kohler 10w30 oil. The temps here are generally mid 80's tow low 90's during the heat of summer. Anyone have any opinions?