Hi Tim,
Thank you so much for the detailed and educational response. That really helps a lot! Would 15W50 be safe to run all year round? What about 10W40?
Are you at all familiar with Castrol Edge RS with Titanium Fluid Strength Technology (FST)? How would you compare it to your recommendations and to Amsoil?
https://www.amazon.co.jp/CASTROL-%E3...qid=1468234195