I converted my Dyna Wide Glide over to Mobil 1 "V-Twin" oil in last weekend. I also put the 70-90W Mobil 1 in the chain case. The problem is that I could not find any 10W40 Mobil 1. All I could see on the store shelves were 0W30, 5W30, and 20W50. I had heard that a lot of manufacturers stopped reccomending 10W40, so a lot of suppliers stopped stocking it. I did have a quart of Golden Spectro 10W40 semi-synthetic at home, which I heard was OK to use....so I used that. Anyone have any experience with Golden Spectro oils ?