I had a supply of the Ram oil that was recommended for my FIct engine. I know this is no longe being made and I need to get some more oil. I called several different dealers and go several different opinions as to which oil I should used. Some said the XD50 and some the XD100. What do you guys think. Also i have a little of the Ram oil left in my resovior, so should i wait until this is all used before I add the new oil.