I was thinking about going to 20-50 wt. syn. in my 17 Springfield for summer. It gets hot,95+ (May thru oct) most of my ride time in the summer. I change oil @ 3500. I would go back to the recommended 20-40 in the fall. Just figured I would hear if there is any pro or con to this Idea? Thanks for any input on this. sorry for the double post of the vanishing side covers, new to this posting stuff.