Amsoil diesel oils are changing in 2017 and AMSOIL synthetic diesel oil’s 5w-30, 0w-40, 5w-40, 15w-40 that exceed API CK-4 and API FA-4 specs have been developed and extensively tested under extreme conditions. With the API introducing two new diesel oil specifications API CK-4 and API FA-4 oil needed to be changed. These 5w-30 0w-40… Continue Reading