Hi all! My first post in this forum, although I have been lurking around reading for sometime. Here's my situation: I have a Lincoln welder with a 23hp Kohler air cooled engine. I bought it brand new in November of 2010, and did the 1st oil change after 5 hours. I put in Petro-Canada Duron XL 0W-30 synthetic blend at that time, and didn't use the machine much over the winter. With spring around the corner and the potential for lots of hard use coming up, I have stocked up on Amsoil ASE for summertime use. My 1st question is: Is the Amsoil ASE my BEST choice for hot summer use. And 2nd question: What would be the BEST oil for next winter, assuming lots of hard use as well. Keep in mind I'm in Canada and can see -30degree weather very often. Thanks.