Fellas i have a 2015 f3s with 13k miles. My (new to me) first oil change, will use oem oil filter, but the oil viscousities are all over the place, 5-40, 10-40,20-50, etc. I like the castrol 4t bike oil full synthetic and plan to change at 4500 miles (just oil) and again at 9k with filters. Can you give me some help on viscouties, and if I am going the wrong way. Thanks Tim I live in Oregon and ride only in summer.